Hybrid Hypermiling - Hybrid EcoDriving

GAS-ELECTRIC HYBRID-DRIVE RECENT HISTORY OVERVIEW: Let me share some recent gas-electric hybrid vehicle history with you here. Hybrid cars started being offered by Toyota and Honda and used on the streets of Japan in the late 1990s. The Honda Insight chassis with its Integrated Motor Assist (IMA) and the Toyota Prius with its First Generation (1G/GEN I/NHW10[Japan]NHW11[U.S.]) Toyota Hybrid System (THS) hybrid gas-electric drive propulsion systems were designed and engineered as gas-electric hybrid cars from the ground up. Honda’s IMA-Powered aluminum-bodied Insight was first offered for sale in the U.S. in 1999. Toyota’s THS-Powered Prius started being sold in the U.S. in 2000 (MY 2001).

The original aluminum-bodied 61/65/70 MPG 2-Door/2-Passenger w/ Hatchback Honda Insight is no longer in production (since 2006), but its Integrated Motor Assist (IMA) Hybrid-drive solution has been bolted into a standard Honda Civic 4-Door/5-Passenger sedan chassis to form what is today’s 49/50/51 MPG Honda Civic Hybrid (HCH). A new 2010 model, 40/41/43 MPH 5-Passenger/5-Door Hatchback Honda Hybrid, was introduced bearing the Insight II nameplate with a 2011 CR-Z Hybrid offered for sale in the USA beginning in August 2010.

Until and through 2003, Toyota offered the earlier First Generation (1G/GEN I) 52/48/45 MPG NHW11 Prius in the U.S. with its gas-electric hybrid-drive solution called the Toyota Hybrid System (THS). This First Generation (1G/GEN I) Prius came in a conventional, 5-passenger compact sedan sized chassis design with a conventional, non-hatchback/liftback trunk.

In 2004, the First Generation (1G/GEN I/NHW11) Prius THS hybrid-drive was upgraded, and its chassis replaced. It was replaced by a new Pre-2008 EPA Test Mode 51/55/60 MPG Second Generation (2G/GEN II) NHW20 Hybrid Synergy Drive (HSD) powered vehicle delivering improved fuel economy along with more electric power in a new, unique low coefficient of aerodynamic drag (Cd = 0.26) 5-passenger 4-Door Sedan Liftback/Hatchback chassis. This 2G/GEN II/NHW20 HSD replaced the 1G/GEN I/NWH11 THS system and has been sold in the U.S. from Model year 2004 through 2009. In the Spring of 2009, the 2G/GEN II/NHW20 was replaced by the 3G/GEN III, 2009½/2010 to today version ZVW30 Third Generation Prius model, including the new "Caddy In A Kimono" Prius v Station Wagon, introduced in Model Year 2012.

2009 is the last year the EPA 45/46/48 MPG (Pre-2008 EPA Method: 51/55/60 MPG) 2G/GEN II Prius was sold. The 2010 3G Prius came out in Model Year 2010. Toyota replaced 2G/GEN II with their battery and hybrid technology upgraded Third Generation (3G/GEN III) ZVW30 Model Prius. The 2010 3G Prius is the “100 MPG” Prius that written about in the news. Its best-case fuel economy per Japan's 10.15 Mode Fuel Cycle was touted as 100± MPG, with a nominal MPG of 75-85. The 2010 3G Prius garnered an Official EPA Fuel Economy Rating of 48/50/51 MPG (using the Pre-2008 EPA Test Method, this 48/50/51 MPG would likely translate into something like 54/60/64 MPG ).

Real-World expectations were that this Next Generation of Prius would deliver a modest 10%-13% improvement in "City" MPG, raising its EPA fuel efficiency rating up from 48 to 51 EPA MPG (Up to 64-68 MPG using Pre-2008 EPA Test Method). These expectations were met.

There are many cars being offered and touted as “Eco-Friendly, Green” Hybrids, but, in my opinion, the only technologically “elegant” gas-electric hybrid solution on the market today is Toyota’s Hybrid Synergy Drive (HSD). Here a listing of the current gasoline-electric hybrid car drive system solutions, versions which are being offered/marketed by Toyota, Honda, Nissan, Ford/Mercury, General Motors (Chevrolet/GMC/Saturn), Chrysler-Dodge, BMW, Mercedes. I will list them next in rank order along with some comments.

1. TOYOTA HYBRID SYNERGY DRIVE (HSD)/FORD HYBRID DRIVE: Toyota’s Hybrid Synergy Drive (HSD) tops the list. Its architecture is a full “Serial/Parallel Hybrid,” and is the only truly “Full-Time” Hybrid System. The Generation II (GEN II/2G) HSD is used in all the 2004-2009 Prius cars as well as the Hybrid Camry, Hybrid Highlander, Lexus LS600hL/LS/GS/RX/HS/CT Hybrids and Nissan Altima Hybrid Platforms. The GEN II/2G HSD was followed by the improved GENERATION III (GEN III/3G) HSD used in the 2010-2013 Sedan Hatchback, and newly launched 1st Generation "vee" Prius v Station Wagon.

However, each uses an ICE displacent size and set of control parameters tailored specifically to each platform. Prius is different from the Camry, which is different from the Highlander, which is different from the LS600hL/LS/GS/RX/HS/CT, which are all different from the Altima.

As previously mentioned, a licensed version of the 2G/GEN II HSD is used in the Hybrid Nissan Altima with 21 licensed hybrid patents from Toyota’s older 1G/GEN I THS used, and incorporated into the Ford Escape/Fusion - Mercury Mariner/Milan Hybrid Drive design solution.

Toyota’s gas-electric hybrid solution combines the characteristics of a pure electric vehicle (EV) drive and a continuously variable transmission (CVT) and uses electricity and control electronics and software in place of toothed gears. The Hybrid Synergy Drive is a drive-by-wire system with no direct mechanical connection between the engine and the driver-operated engine controls. Both the gas throttle pedal and the gearshift lever in an HSD equipped car merely send electrical signals to a control computer, which manages and handles operation.

The 2G/GEN II HSD hybrid system as installed in the 2004-2009 Prius, delivers an approximately 71% increase in CITY DRIVING fuel economy over what the 1.5 Liter I-4 ICE in the Prius would deliver were it to be utilized to power and drive the Prius chassis in a non-hybrid, conventional "Otto Cycle" gasoline-powered application. The new 3G/GEN III 2010 Prius replaced the 1.5 Liter I-4 ICE with a 1.8 Liter I-4 along with adding some new fuel saving technologies. This change resulted in an ~6% increase in Official EPA CITY fuel economy.

2. HONDA INTEGRATED MOTOR ASSIST (IMA) HYBRID DRIVE: The architecture of Honda’s Integrated Motor Assist (IMA) is more a “Serial Hybrid” or Power Assist Parallel gas-electric propulsion system. It comes in second on my list, a close second, but still second. As the “Assist” in the IMA name implies, it is not a “Full-Time,” hybrid drive, whereas, Toyota’s HSD is “Full-Time.” The basic IMA Hybrid System and follow-on -2, -3 and -4 generations of added technical enhancements, is used to power the original Honda Insight, Accord and Civic Hybrid (HCH) cars as well as follow-on versions of the HCH. The new 2009½/2010 Global Small Honda Hybrid (GSHH), Insight II, was introduced in the Spring of 2009. The 2011 CR-Z Hybrid, which hit showrooms in August 2010, has the most recently updated iteration of the H-IMA solution.

Honda’s IMA hybrid car technology uses an electric motor mounted between the engine and transmission to act as a starter motor, engine balancer, and traction-assist motor. In its first generation, IMA did not function to power the car on electricity alone, and could only use the electric motor to assist or start the ICE. Beginning with the 2006 Civic Hybrid model, control software changes facilitated activation of the IMA electric motor in the EV (Electric Vehicle) mode while the vehicle is coasting without activating the ICE.

Compared to Toyota’s Hybrid Synergy Drive (HSD) or the GM/Daimler-Chrysler/BMW Two-Mode (2Mode) Hybrid, the IMA Hybrid has a less powerful motor-generator. The smaller motor-generator permits the IMA Hybrid to slow or stop its rate of deceleration by a lesser extent compared to the HSD and 2Mode hybrids equipped with larger motor-generators. Additionally, the IMA-Powered Hybrid cannot operate without mechanically turning over the ICE, which is directly mechanically coupled in series with the electric motor-generator.

The IMA Hybrid system as installed in the Honda Civic Hybrid (HCH), Insight II, and CR-Z delivers an approximately 63% increase in CITY DRIVING fuel economy over what the 1.3 Liter I-4 HCH ICE [1.5 Liter version in CR-Z] would deliver were it utilized to drive the Honda Civic/Insight II/CR-Z chassis in a non-hybrid, conventional gasoline-powered application.

3. GENERAL MOTORS CHEVROLET VOLT E-REV/REEV SERIAL HYBRID DRIVE: The Volt's Voltec drivetrain has a single planetary gear set, a pair of electric motors and gasoline-powered engine. Unlike the Generation I, II and III Toyota Prius, and its plug-in, PHEV version due out in 2012, all which are parallel gas-electric hybrid cars whose electric battery, gasoline engine or both in combination can propel them, the Chevrolet Volt is essentially a plug-in, gasoline-electric serial hybrid car. At speeds below 70 MPH, electric drive motors on its wheels propel the Volt 100% electrically from power supplied from the battery and main electric bus. These drive motors receive electric power from a common, shared Direct Current (DC) Bus. Electric power to the DC Bus is supplied by the Volt’s traction battery or its onboard, gas-fueled engine-generator.

The Volt's power-train design is centered on it being an Electric Vehicle (EV), meaning it is designed to be powered primarily by its 400-pounds of onboard Li-Ion Traction Battery, which must be charged up by being plugged into the public power grid or other suitable electric power source external to the Volt vehicle. It has a secondary, battery backup power mode, which is provided by an onboard, auxiliary conventional gasoline-fueled internal combustion engine (ICE) that turns an electric generator whose electric output is switched online to power the drive wheels when the traction battery charge is depleted.

When operating in the Charge Sustaining (CS) Mode at speeds of 70 MPH and above, the ICE is switched from powering and driving the wheels via connection to electric generators that electrically drive the wheels, to having the ICE powering, driving, and providing motive force to the wheels via direct mechanical coupling. This is done to gain an additional 10 to 15 percent of operating efficiency at higher Interstate-Freeway-Highway cruise speeds.

GM calls this backup, auxiliary gasoline engine a “Range Extender” engine. This 1.4 Liter I4 "Range Extender" auxiliary engine used in the Volt is the premium gasoline burning, non-Turbo (LUU) version of the DOHC Ecotec 1.4L I-4 VVT Turbo (LUJ) engine currently used in the Chevy Cruze. The range-extender engine is married to an electric generator. The primary function of this range extending engine-generator combination is to serve as a fallback, secondary electromotive power source to backup the Li-Ion traction battery array when it can no longer power the drive motors due to lack of an electric charge.

In the course of normal operation, the engine-generator will automatically start up and kick in to supply electric power to the Volt when its battery no longer can. When in this "Normal Mode" of operation, this "Range Extender" engine-generator does not automatically charge the traction battery with excess energy scavenged from the ICE, as the parallel hybrid design used in the Prius does. However, the "Range Extender" engine-generator can be manually switched on to operate in a traction battery charge sustaining and assisting mode, CS-Mode (battery depleted, gasoline engine on and driving a generator to provide electric power to the batteries), by use of the “Drive Mode” button.

Depressing this “Drive Mode” button will switch the Volt out of its default, regular “Normal” operating mode (Range Extender Engine-Generator not normally on), and put it into either the “Sport” or the “Mountain” mode. Switching the Volt into these enhanced performance "Sport" or "Mountain" modes causes the Range-Extender Engine-Generator to be switched on, and connect into the E-REV/REEV system full-time to provide supplemental electrical power to sustain the charge of the traction battery along with supplying additional electric power to the drive wheels. As their "Sport" and "Mountain" names imply, these performance-boosting modes are used to provide added zip, acceleration ("Sport") or added electric power for climbing hills, mountains or inclines ("Mountain"), but at the expense of burning Premium Unleaded priced gasoline and lowering fuel economy.

The E-REV acronym used by GM-Chevrolet to describe the Volt design stands for Electric-powered with Range Extender gasoline engine-generator Vehicle. Another term commonly used to describe the Volt is Ranged Extended Electric Vehicle (REEV). When the Volt is operating in the pure battery-driven EV mode, it uses no gasoline. When the Range Extender gasoline engine-generator is caused to fire up and kick in, the Volt’s incremental, instantaneous miles-per-gallon of gasoline fuel economy becomes, essentially, the inherent fuel economy of the onboard Ecotec 1.4L I-4 VVT Turbo engine that turns the electric generator less any power transfer losses.

Depending on traffic and weather conditions, terrain, air conditioning and heater usage, operation of electrical features-accessories, driving style, and how heavy a foot one uses on the throttle pedal, the Volt can travel up to 40± miles on a single, full charge of its Li-Ion Traction Battery. Per the GM/Chevrolet performance specifications listed on their official Volt website, the backup, auxiliary gas-powered engine-generator will kick in at the point the onboard Li-Ion traction battery becomes drained, depleted. In this secondary, backup power mode, the gas-powered range-extending engine-generator will then supply electricity to propel the Volt another "several hundred additional miles” or up to 300± miles. The 300± miles extended-range distance is "best-case," and assumes the Volt has a topped off, full tank of gasoline when switched into this secondary power mode that backups up the traction battery when it becomes depleted.

The 40-miles powered by battery alone added to the 300-miles powered by the gasoline engine alone gives the Volt a 340-mile range or a best-case maximum usable circumscribed radius of action travel distance from Point "A" – To – Point "B" & Return of 170-miles, without being recharged and refueled.

FWIW, Prior to the date of this revision to my 10-Tips article, GM/Chevrolet was keeping the size of the gas tank a closely held secret. Back in November 2009, Edmunds-INSIDE LINE reported the gas tank size would be 8-gallons, and went on to speculate that the Volt would get 38± MPG in the Battery Backup, Charge Sustaining Mode. The size of the Volt’s fuel tank has now been confirmed to be 9.3 gallons, and the official EPA Combined City-Highway Fuel Economy displayed on the new EPA "Monroney Sticker" is 37 MPG.

As a point of reference, the official EPA MPG Fuel Economy numbers of the 2011 Chevrolet Cruze powered by the 4-cylinder, 1.4 Liter engine w/ Automatic (S6) transmission burning Regular Unleaded is 24 City/28 Combined/36 Highway. Taking this 9.3 gallon tank size, and assuming 1.3 gallon emergency reserve, leaves 8.0 gallons of fuel. Using a 34 MPG number, which is closer to what the average driver might see, and doing the math, results in [8.0 gal + 1.3 gal] x 34 miles/gal = 272.0 miles (base) + 44.2 miles (reserve) = 316.2 miles range at "dry tank." This 316-miles range number is within the “…make sure we get over 300 miles of fuel range,” Volt Chief Engineer, Andrew Farah, is targeting.

Using the new, recently published EPA sticker numbers for the 2011 Volt, we see EPA promising 35-miles running "All Electric" on EV-Battery drive, and 344-miles more running on "Gas Alone," with the "Range Extender" auxiliary engine operating in the “Normal” Battery Backup, Charge Sustaining (CS) Mode. Combining these numbers yields 35 + 344 = 379 miles as a maximum range number at “Dry Gas Tank.”

We will just have to wait and see exactly what the MPG-FE for the Volt is in the CS-Mode with the 1.4 Liter I4 "Range Extender" auxiliary engine operating in the “Normal” Battery Backup, Charge Sustaining (CS) Mode.

I estimate that the average driver, operating in average driving and all-season weather conditions, will probably see "Range Extender" auxiliary engine gasoline-powered operating fuel economies in the High 20s-To-Low/Mid 30s MPG range.

Considering the above, I guesstimate the maximum driving ranges in the Battery-EV Plus Range Extender Mode for the average “Just Drive It” John or Jane Q. Volt-Driver will likely be something less than the 35 miles + 344 miles = 379 miles advertised by GM/Chevrolet and EPA. I think it will probably fall closer to something like 285-325 miles Max Range running the Volt to ““Dry Gas Tank.” More practically, it will be 250-285 miles until the Low Fuel Warning light illuminates telling you are running on your emergency reserve fuel, and better find a gas station ASAP.

Bottom-line, if you get invited to Mom’s, Grandma’s or Aunt Martha’s house for Thanksgiving or Christmas Dinner, and the dear darlings live less then 300-miles away, you should be able to make the motor trip there in a Volt nonstop. This assumes you roll out of your driveway with a full battery charge, a topped-off tank of gas, and drive EV-Hybrid $mart all the way there.

4. GM/DAIMLER-CHRYSLER/BMW TWO-MODE/DIRECT HYBRID DRIVE: The Two-Mode (2Mode) Hybrid Solution was jointly developed by General Motors/Daimler-Chrysler/BMW to power heavy curb-weight, large mass-transit “city bus” sized vehicles. Its Two-Mode design means it is not a “Full-Time” hybrid drive system. It was developmental test and evaluated and “Pilot Tested with Limited Field Deployment” in the 1990s. As part of this Pilot-Limited Field Deployment, a few hundred city mass-transit buses were put into service in selected cities, mostly in Europe, but otherwise it was shelved without broader follow-on deployment and expanded application into private passenger vehicles until recently.

Although it had been shelved by General Motors Corporation prior to the New Millennium, when $100-per-barrel oil approached and $3.00+ per gallon gas happened, GM quickly resurrected and re-embraced the “Mass-Transit Bus-Sized” Two-Mode gas-electric hybrid power solution. They quickly brought it down off the shelf, dusted it off and down-sized and tamped it into and under the hoods of their Full-Sized 2008 GMC Yukon/Chevrolet Tahoe "Family Bus-Sized" SUV Trucks to power these mega-tonnage Gas-Guzzling “Beasts.” In addition, at the Washington Auto Show in January 2008, General Motors Corp. announced it had received orders for 1,732 Two-Mode (2Mode) Hybrid buses from transit agencies in Washington, Philadelphia and Minneapolis/St. Paul.

The Two-Mode (2Mode) Hybrid System employs a special electronically variable transmission (EVT) with two integrated motor-generators along with using special fuel saving ICE technologies that include cam phasing, variable valve timing (VVT) and Active Fuel Management™ cylinder deactivation technologies. These elements working together, deliver an overall improvement in fuel economy over the equivalent non-hybrid Yukon/Tahoe versions of 40% to 50% City MPG/25% Highway MPG. Two-Mode (2Mode) Hybrid Yukons/Tahoes are now being offered in limited availability qualities for Model Year 2008 with a Two-Mode (2Mode) Hybrid version of the Saturn Aura/Vue and Chevrolet Malibu offered in 2009.

Although the 40% to 50% City MPG/25% Highway MPG improvement is a good improvement in fuel economy on a percentage basis, the Two-Mode (2Mode) Hybrid Solution comes in a distant third compared to the HSD and ISA enabled gasoline-electric hybrid vehicles on total delivered miles per gallon fuel economy. The HSD and IMA used in the 51/55/60 MPG Prius and 46/48/51 MPG Civic deliver twice to three times the MPG-FE that is delivered by heavy curb-weight Two-Mode Hybrid enabled truck-sized 21/21/22 MPG Yukon/Tahoe vehicles.

The “Two-Mode” designation comes from the hybrid’s two operating modes that can function singularly or in parallel. One mode is optimized for city driving and the other for highway driving. Under light loads and at low speeds (City Mode), the Two-Mode system can operate either on its electric motors and battery pack or on internal combustion engine (ICE) power alone, or using a combination of the two modes. At higher speeds and with heavier loads (Highway Mode), The Two-Mode (2Mode) Hybrid System switches to the second mode that runs mainly on the gasoline engine with electric motor-battery available and assisting as and if needed for added power to climb steep grades, tow a trailer, or for added acceleration oomph during passing.

Any and all “hybrids” you may see being offered/planned to be offered by General Motors/Chrysler-Dodge/Mercedes/BMW in the upcoming model years, will be based around and incorporate this Two-Mode (2Mode) Hybrid System that was jointly developed by GM/Daimler-Chrysler/BMW to power heavy curb weight SUVs and "bus-sized" heavy-vehicles.

5. CHEVROLET/SATURN “GREEN LINE/ECO eASSIST” MILD-HYBRID DRIVE: This hybrid solution is a “Mild Hybrid” [Belt Alternator Starter (BAS) system with Auto-Stop]. It was originally called “Green Line” by Chevrolet/GM, but now is being called "ECO eAssist." When compared to the Hybrid Synergy Drive, Integrated Motor Assist, 2Mode/Direct, and E-REV/REEV gas-electric hybrid solutions discussed above, this fuel conserving solution comes in last and resides at the bottom of the hybrid technology barrel.

The Battery Alternater Starter solution is what I call a marketing solution that was cobbled together by General Motors for the Chevrolet Malibu and old Saturn Aura/Vue when they were scrambling to become “Eco-Green” and “Fuel-Efficient” overnight. GM had their engineers throw together a quick and dirty "Battery-Alternator" motor-generator “techno-kludge.” This "Mild Hybrid" solution is essentially using an over-sized car-battery to power an electric motor-generator permitting the “Hybrid” Chevrolet Malibu and old Saturn Aura/Vue to run off battery power for short periods.

The original "Green Line" BAS solution has been tweaked and refined into the "ECO eAssist" mild hybrid BAS system that debuted at the 2011 New York Auto Show. This next generation BAS mild hybrid system show car was an EPA 26 MPG City/38 MPG Highway 2013 Chevrolet Malibu ECO model powered GM/Chevy's 2.4-liter Ecotec four-cylinder aided by the aforementioned ECO eAssist BAS solution. This revised BAS ECO eAssist system is the same one used in the new "mild hybrid" "eAssisted" Buick LaCrosse and Regal cars introduced in CY2012.

The new ECO eAssist [revised old Green Line "Mild-Hybrid" Belt Alternator Starter (BAS) w/ Auto-Stop] system basically functions like a battery-alternator powered turbo-charger, which gives an extra bit of "e-Assist" propulsion oomph to the gasoline engine through a large "starter motor." This Belt Alternator Starter (BAS) system employs a special oversized "starter motor" in combination with an oversized, up-voltaged 36 Volt car battery (i.e. essentially electrically equivalent to three (3) standard 12 V car batteries connected in electrical series, 12V + 12V + 12V = 36V). The battery in this new ECO eAssist offering has been upgraded to use lithium ion (Li-Ion) battery technology.

The Battery-powered Alternator-Starter assists and mechanically turns over the non-operating internal combustion gasoline engine (ICE) to power the vehicle from a dead-stop until a certain speed (i.e. "Gasoiline Engine Start-Up" RPM level is reached) or to provide a quick boost in acceleration while moving down the road. Once "Start-Up" RPM is reached when starting from a dead-stop or a foot throttle request for an added spurt of acceleration occurs while already moving, the gasoline engine "fires-up" to provide increased power as it operates using the "Otto Cycle" of the car's conventional gasoline engine.

As with a typical starter motor, the electric motor in the "Mild-Hybrid" BAS is not connected directly to the main driveline power train. The gasoline engine starts operating after being spun-up by the BAS eAssist. The BAS eAssist electric motor overcomes the initial starting inertia and propels the vehicle using electric power, not gasoline-power, which is how "Mild-Hybrid" BAS System works to incrementally save fuel. In addition, fuel to the gasoline engine is automatically shut off when the vehicle is coasting, braking or stopped.

The ECO eAssist (old Green Line) Mild-Hybrid BAS installed in the new Chevrolet Malibu, Buick LaCrosse and Regal, and old Saturn Vue/Aura does seem to provide some small improvement in fuel economy (approximately 10%), while keeping complexity to a minimum.

There, I have given you a brief overview tutorial on and about gas-electric hybrid vehicles offered/being offered here in the U.S.

FIRST, THE BAD NEWS: If you choose to drive your new hybrid car using the same Gas-To-Go/Brake-To-Stop driving techniques you used to drive the conventionally powered car it replaced, your miles-per-gallon fuel economy numbers will not be remarkable. The MPG-FE numbers probably will be much like it was being solely powered by the conventional gasoline powered Internal Combustion Engine (ICE) installed in it to power the ICE portion of the hybrid gasoline-electric propulsion system.

I once owned a 1992 Honda Civic CX. It was conventionally powered by a standard "lean-burn" 70 hp gasoline-powered Honda In-Line 4-Cylinder "Otto Cycle" ICE, which delivered an EPA 42 City/45 Combined/48 Highway Estimated MPG and 41 "Around Town"/48 "Open-Road," as measured by me using the Multiple-Tank-Refill Method.

The gasoline-powered portion of the Prius Hybrid Synergy Drive system is powered by 76 hp Toyota In-Line 4-Cylinder ICE, operated on the "Atkinson Cycle." Toyota's 76 hp In-Line 4-Cylinder ICE is similar in size, weight and power to 70 hp Honda Civic CX ICE. This means that the inherent, nominal gas mileage of the Prius In-Line 4-Cylinder ICE is probably the same as the 41/48± MPG delivered by the ICE of my old Honda Civic CX.

Therefore, if your Prius is delivering less than or equal to 41-48 MPG-FE, you probably are driving your gasoline-electric Prius hybrid using the same fuel consumption inefficient driving techniques you use to operate 100% conventionally powered cars, and causing the gasoline engine to run more than it needs to run. The consequences of your "Hybrid Unfriendly" driving habits and operating techniques are that you are effectively "bypassing/overriding" the fuel economy contribution benefits available from the electrical energy regenerating, recovering and storage portions of the gas-electric hybrid system.

Continuing to use such old, “hybrid unfriendly” driving techniques, and not driving “Hybrid Smart,” will prevent you from “reaping” the incremental fuel economy “harvest” that is available from the battery and regenerative motor-generator and braking elements of the hybrid gasoline-electric system design.

A BIT MORE NOT SO GOOD NEWS: Unfortunately, most drivers lack the inclination, dedicated driving discipline and frugality required to “work” at learning to optimally drive their hybrid car, as a hybrid car must be driven to facilitate it delivering its maximum fuel economy benefits and truly stellar real-world MPG.

Most first-time hybrid car owner-operators lack prior knowledge on the optimal operation of a hybrid vehicle. As a result, when they pick their new hybrid up at the dealer, and drive it off the lot, they do so using the same Gas-To Go/Brake-To-Stop operating manner they used driving the old 100% conventionally powered autos their new hybrid car replaced. These conventional foot throttle pedal punching and brake stomping Gas-To-Go/Brake-To-Stop driving techniques, used to operate “conventionally powered” vehicles, are the same ones most drivers have used ever since they got their driver’s license back in high school and first started driving.

Bottom-line --- Driving hybrid cars with a heavy gas throttle and brake pedal foot will result in poorer miles-per-gallon/liters-per-100 kilometers fuel economy as compared to if they are driven in a “Hybrid Friendly - Hybrid $mart” manner.

NOW, THE GOOD NEWS: The good news in driving any car is that, according to testing by Edmunds.com, aggressive drivers who moderate their aggressive Gas-To-Go/Brake-To-Stop driving habits can improve their overall gas mileage by as much as 37-percent. Additionally, an aggressive driver can glean a 14-percent gain in fuel economy by simply staying below the Posted Maximum Legal Speed Limit and ratcheting back on their travel cruise speed.

EPA estimates that every 5 MPH incremental increase in travel speed above 60 MPH is like having to pay an extra 25-cents per gallon of gasoline at the pump.

The rest of the good news…even if a driver operates a hybrid car like he or she is still driving their old conventional, 100% Internal Combustion Engine (ICE) powered car, it will still deliver “GOOD,” EPA Matching MPG-FE, just not "STELLAR” MPG-FE, as defined by driving to surpass the EPA MPG-FE estimates. This is because Toyota, Honda and General Motors engineers have optimized the design of the Hybrid Synergy Drive (HSD), Integrated Motor Assist (IMA), "Green Line” Belt Alternator Starter (BAS) "Mild-Hybrid" and Two-Mode (2Mode) gas-electric drive-system control hardware and software of their hybrid vehicles around the driving behaviors and expectations of a "typical driver.” Of course, their assumed "typical driver” is one who only knows how to drive and is experienced in driving an Internal Combustion Engine (ICE), 100% conventionally-powered vehicle.

To cause your hybrid vehicle to regularly meet or surpass the EPA MPG-FE estimates, you have to "learn" to let the HSD, IMA or other hybrid system do the job it was designed to do by "staying out of its way" and stop using old "energy robbing" driving behaviors and techniques. You will find that adding, integrating and unobtrusively applying new hybrid-focused driving behaviors and top-level, elemental Hybrid Hypermiling Driving Techniques into driving your gasoline-electric hybrid car is a reasonably painless process.

Your efforts will be rewarded with delivery of "stellar" MPG-FE and not having to "pay at the pump" as much or as often as you did before you started driving your hybrid vehicle.

The more you learn to "Drive Hybrid Smart," and work as an integral part of the HSD, IMA, "Green Line" BAS, Two-Mode (2Mode) or other hybrid system solution and their various features, the more you will converge on meeting or surpassing the EPA Miles Per Gallon (MPG) Fuel Economy (FE) Rating numbers promised on your hybrid "fuel-sipper" of choice's window sticker.

LEARNING TO DRIVE "GREEN" TO $AVE "GREEN BACK" PETROLBUCK$...$$$$: Face it, gas prices will likely never be going down for very long. They never have in the past and will probably not start now.

Gas is selling for $3+ per gallon on its way to $4 and beyond, not 25¢ as it was when the fuel wasting on-road driving behavior norms of today were formed. Whether we realize it or not, we all are now driving under a new fuel consumption and energy use paradigm.

Where a car once used to be a mechanized, gasoline-powered personal and family transportation work of art that functioned as one's personal noble steed, it has since become a heavily government controlled and regulated transportation appliance whose fuel use generates tax revenue for the government.

I recognized this paradigm shift back a few years back, when gasoline was still selling for well under $1.499 per gallon. At that point, I purchased the hybrid Prius, and changed the driving and fuel consumption behaviors and techniques under which I operate my personal vehicle, successfully transforming myself into a Hybrid Pseudo-Hypermiling / EcoDriving Zen Master.

With the expectation that $140± per barrel oil and $4.00± per gallon gasoline in pursuit of $5, $6, $8, $10+ and beyond returning, most "$mart Folks" out here in the Yankee Doodle hinterlands have started driving to save "Green" and will do anything "legal" to save a "Green Back" PetrolBuck.

I have transformed my previous Porsche Throttle-Pedal Honed driving habits and behaviors, and learned how to "Drive Hybrid Smart" by becoming an "intelligent" part of the Gas-Electric Hybrid Man-Machine Interface. I now drive with a feather-light, deft touch on the foot throttle. In Zen-like fashion, I have Become One With Prius Hybrid Synergy Drive (HSD), thereby, permitting it to regularly deliver "$tellar" MPG-FE, and Green Back $avings to me.

I employed a combination of fuel economy enhancing "in-garage" pre-operative set ups along with "on-road" operative Hybrid Pseudo-Hypermiling / EcoDriving Techniques to pre-operatively set up and operate my 2G, Generation II Prius, and now to my new, 2012 Prius v fuel-sippered that replaced it. Using these techniques permits me to achieve money saving MPG-FE performance, and decrease the frequency and amount of making my Gas Tax "donations" to money hungry Big Government.

My Hybrid Pseudo-Hypermiling / EcoDriving assured that I regularly meet or beat the old Pre-2008 EPA 51 Highway/55 Combined/60 City Estimated MPG-FE numbers for my 2G Prius, and now facilitates me surpassing the 2008 EPA 44 City/42 Combined/40 Highway Estimated MPG-FE numbers for my new in 2012 Prius v.

Yes, it does require a bit of "Hybrid Driving Work," which for me has become second-nature "Hybrid Driving Play"... or should that be "Hybrid Driving Pay"... as in "Pay Day."

My Hybrid Hypermiling enhanced EcoDriving is saving and "Paying" my family and me "Big PetrolBucks" by minimizing our family’s monthly "fuel burn rate" and total annual gasoline fuel expenses. Hybrid Pseudo-Hypermiling / EcoDriving has reduced the monthly auto fuel expenses for my family's primary transportation vehicle by ~80%. At the mid-year peak to $4.00± per gallon for gasoline prices in 2008, this reduced the projected annual fuel expense for our primary transportation vehicle from $4310± down to $890±. The 80%, $3420, annual savings rate made the Family CFO, my wife, "Hybrid Happy."

DRIVING *HYBRID $MART*

HYBRID BASICS FOR IMPROVED MILES & "$MILE$" PER GALLON

(10 “Best Practices” For Achieving “$tellar” Fuel Economy In An OEM Instrumented Prius)

A. LOOSE OLD-BAD, DEVELOP NEW HYBRIDIZED DRIVING HABITS

B. MPG VS. MPH "SWEET SPOT" RANGES

C. ROLLING FRICTION AND TIRE SELECTION

D. ICE FRICTION AND MOTOR OIL SELECTION

E. HVAC OPERATION

F. CONTROLLING THE HYBRID SYNERGY DRIVE (HSD)

G. "ICE" COLD START/RESTART

H. "INFINITE" INSTANTANEOUS MPG-FE

I. "ELECTRO-GLIDING"/FULL-TRACTION BATTERY ARRAY "EV" MODE

J. "OPEN ROAD" CRUISE "SWEET SPOT"/ECC USE - DASH (pULSE) & COAST (gLIDE)

A. LOOSE OLD-BAD, DEVELOP NEW "HYBRIDIZED" DRIVING HABITS-BEHAVIORS: Unless you are "miraculously" already driving "Hybrid Smart," you need to "loose" and "hybridize" the old, bad "Gas-To-Go/Brake-To-Stop" driving habits and behaviors you are using when you drive.

"Hybridize" your driving attitude and practices by accelerating moderately, avoiding Jack-Rabbit starts, doing more "Free-Wheeling" Coasting and staying away from last minute hard brake pedal stomping stops. Try to smooth out your travel profile by minimizing application of your friction brakes and gas throttle in Stop & Go traffic. Anticipate GREEN-to-RED and RED-To-GREEN traffic light changes, the ebb and flow of traffic and drive to maintain minimum fuel consumption at a steady and safe speed.

Adopting a ripe tomato/eggshell-under-the-pedal style, feather light touch for operating both your foot-throttle and brake pedals will pay off with greater gas mileage numbers by minimizing fuel wasting behavior and gaining velocity-sourced energy reclamation from the energy regeneration subsystem of your hybrid vehicle.

The Fuel Economy points here are:

1. Gas-To-Go "Smarts": The "Beating-Everyone-Off-The-Line" when the "Red" Traffic Light changes to "Green" only to race them to the next "Green" traffic signal turning "Yellow-To-Red" is a common "around town," in-traffic "gas guzzling" driving behavior that incrementally "robs" fuel economy from you. This is true whether you are driving in a conventionally-powered vehicle or a hybrid-powered one. Most people use this "Gas-To-Go" driving behavior because they are mirroring the lemming-like behavior of the rest of the "traffic herd."

This stomp the "Gas-To-Go" driving behavior norm was born and established when a gallon of automobile fuel cost 25¢ a gallon. Through the intervening decades, it has persisted, flourished and been accepted as "normal and mainstream" in-traffic group driving behavior. In today's "Brave New World" where crude oil can sell for $140+ per barrel oil, gasoline for $4.00+ per gallon, and you now driving a gas-electric hybrid, such "Gas-To-Go" stomping the foot throttle pedal DOES NOT COMPUTE for you on your 21st Century "Green" Commute.

I have not driven all the hybrids, but all those I have seen are instrumented much like the Prius Hybrid Synergy Drive (HSD). The difference with the Prius and other Hybrid instrumentation, as compared to that in a conventionally-powered car, is its Multi-Function Display (MFD), Multi-Information Display (MID) or a Hybrid System Information (HSI) "Smart Eco-Gauge" that graphically or numerically displays and instantaneously feeds back the effects of any latent "bad, gas guzzling traffic herd" driving behaviors a hybrid driver may have retained in real-time.

If a newbie, novice, new hybrid owner-driver complains "The displayed MPG is below Official EPA Fuel Economy. There is something wrong with my car." --- It is likely that the source of this low MPG fuel economy is located behind the steering wheel and not anywhere in the hybrid system.

If the driver uses this MPG-FE and ICE/Battery operating state feedback constructively, their instantaneous incremental MPG-FE will start to ratchet up and improve markedly. If, on the other hand, they choose a "No One Is Going To Tell Me How To Drive, I'll Drive Like I Always Have" behavior, and ignore the displayed feedback, attainment of "Stellar" Ultra-High MPG-FE numbers will continue to allude them.

OPERATING TECH NOTE: Try this technique to optimize and maximize MPG-FE in an OEM instrumented Prius Hybrid when accelerating from a dead stop to speeds up to 55± MPH (88± KPH). First, depress the foot throttle pedal around 1/3 to 2/5 (30% to 40%), as required to get and keep the instantaneous Miles-Per-Gallon (iMPG) number displayed on the MFD/MID reading about and at least one-half (½) that of the instantaneous Miles-Per-Hour (iMPH) reading shown on the speedometer display. With practice, you will find the "feels right to your foot" pedal depression amount by refining and fine-tuning the actual amount of throttle pedal "push" needed that to achieve the "½" value until you can hit it every time.

Using the "½" Value Rule-Of-Thumb makes doing the iMPG = iMPH/2 math in your head easy as you accelerate from a dead stop in the traffic "herd" to your desired steady state speed while conserving fuel.

For example, if your desired steady-state travel cruise speed is in the range 45-55 MPH, hold an instantaneous Miles-Per-Gallon reading of at least one-half (½) the instantaneous Miles-Per-Hour (iMPH), iMPG = iMPH/2, on the accelerator position until you reach approximately 35-45± MPH or approximately 20%± less than your intended steady-state travel cruise speed below 60 MPH. As you reach that transition speed point, start "feathering" back on the throttle pedal from reading iMPG = iMPH/2 on the MFD to produce an instantaneous reading of iMPG ≤ 1.2 x iMPH on the MFD display as you are passing through 40-50 MPH speed range on your way to economical fuel use-cruise speed, MPG vs. MPH value.

After the 35-45± MPH point is reached, begin lightly easing up on and "feathering" slightly back on the throttle pedal with your foot to get and keep the instantaneous Miles-Per-Gallon (iMPG) fuel consumption displayed on the MFD reading to a number equal to or slightly less than 1.2 times the instantaneous Miles-Per-Hour (iMPH) displayed on the speedometer. Do this as you "seamlessly" ease into and converge on your desired steady-state 45-55 travel speed while gaining postive incremental fuel economy.

When and if road conditions, terrain and traffic patterns permit it, strive to maintain iMPG ≤ 1.1 To 1.2 MPH during steady-state for cruise speeds between 45 to 55 MPH. Doing this either manually or by using the Electronic Cruise Control, will keep the ICE operating in or around the "Sweet Spot" RPM range that delivers optimal miles-per-gallon fuel efficiency in that range of speed. The MPG vs. MPH cross-over point is around 55 MPH. Typically, cruising at 55 MPH on a level road with HVAC OFF, and Outside Air Temperatures of 75°F± will deliver around or about 55 iMPG fuel economy [Refer to the Fuel Economy Expectations Graph to get an idea of the typical MPG vs. MPH for constant travel speeds above 55 MPH].

If you are an owner-driver of the new 2010-2013 3G sedan hatchback Prius, you can use the Hybrid System Indicator (HSI) screen of the Multi-Information Display to select and maintain the optimal foot throttle pedal depression amount that will minimize Per-Tank-Full fuel consumption, thereby, maximizing your overall MPG-FE.

The graphic of an annotated screen shot of the 3G HSI that follows, shows the driving-operation zone that will deliver Optimal Acceleration While Minimizing Overall Per-Tank-Full Fuel Consumed. This portion on the right end of the bar, marked with "GREEN BRACKET LINES," is the zone on the bar where a driver should keep the energy, fuel consumption operating point at during acceleration.

For the new in 2012 Prius v Station Wagon, this iMPG = iMPH/2 operating point is conveniently reached and observed by keeping the top GREEN LINE, #12, on the HSI illuminated. This 12th, top "GREEN LINE" is just before the "RED LINE" POWER ZONE on the HSI Power Zone.

"Purest" OEM Prius owner-operators like me apply the Foot Throttle Pedal Depression and "Feathering" iMPG = iMPH/2 - Transitioning To - iMPG ≤ 1.2 x iMPH Acceleration-To-Cruise Speed Technique Rule-Of-Thumb or skillfully manage Hybrid System Indicator Energy-Power Bar to aid them in keeping their Prius 2G, 3G or "vee" ICE running in the Fuel-Economy "Sweet Spot" RPM zone of the engines's operating "Power" band during acceleration, and to fuel-efficiently converge on a steady-state travel cruise speed.

This permits driving fuel efficiently without having to use an added-on, non-OEM tachometer or other special external instrumentation like ScanGauge II™ or CAN-View™.

Regular use and mastery of the foot throttle pedal depression and "feathering" control technique, in the 2G, or controlling energy, fuel consumption point on the bar of the HSI, in the 3G, or top "GREEN LINE" of the Prius "vee" HSI by the "purest" OEM Prius Hybrid driver will pay them fuel economy dividends.

Prius Hybrid drivers who accelerate from a dead-stop keeping at iMPG = iMPH/2 and in the "GREEN BRACKETED ZONE" followed by efficiently transitioning to their selected steady-state travel cruise speed using these "Hybrid Smart" techniques will consume and waste less fuel on an overall Per-Tank-Full fuel economy basis.

INCREMENTAL FUEL ECONOMY NOTE: Anecdotal reports from Prius 2G hybrid drivers are that regular, skillful application of this Start-Up-To-Cruise iMPG = iMPH/2 - To - iMPG ≤ 1.2 x iMPH throttle pedal control technique can increase incremental Overall Per Tank-Full Average Fuel Economy by 2± MPG.

2010-2013 3G drivers who regularly keep the bar on the HSI screen in the Optimal Accelaration "GREEN BRACKETED ZONE" or 2012-2013 "vee" drivers the top "GREEN LINE" when accelerating from dead stops, are reporting similar gains in overall fuel economy.

2. Brake-To-Stop"Smarts": The "Beating-Everyone-To-The-Next-Red Light" only to execute a "Brake-To-Stop" maneuver or not anticipating ahead of time the need to slightly ease back on the throttle to decelerate and coast to an upcoming "Red Light" you expect will be changing to "Green" before you get there will cost you "Gold & Green" --- Black Liquid Arabian Gold & Green Backs. This mindless, habitual accelerating and racing from one "Red" stop-light after it changes to "Green," to the next "Green" traffic light getting ready to turn "Yellow" and then "Red" is an all too common in-traffic, "gas guzzling, fuel wasting" City-Driving behavior that "steals" incremental fuel economy. This fuel economy "theft" occurs whether you are driving in a conventionally powered vehicle or in a hybrid-powered one.

Not anticipating a "Red" turning traffic signal, a stop sign, coasting and slowing to pull in to a shopping center or just slowing to pull into your driveway will "rob" you of chances to conserve energy you already expended to get you up to travel-cruise speed as well as opportunities to reclaim-regenerate "MPG-FE" by converting that velocity energy into electrical energy stored into the hybrid's traction battery array.

As with the "Gas-To-Go" driving behavior, most people habitually use this "Brake-To-Stop" behavior because they are mirroring the behavior of or being "pressured" by the I-Got-Places-To-Go...You-Are-In-My-Way...Gotta-Get-To-The-Gas-Station-Ahead-Of-You-Before-The-Prices-Go-Up-Again "Flow-Of-Traffic Traffic Herd" who are beeping, bleeping and looming up in their rearview and side view mirrors to get them waste fuel to speed to an upcoming "Red" Traffic Light only to then rapidly "Brake-To-Stop" once again.

OPERATING TECH NOTE: In a Prius NWH20/2G/GEN II Hybrid, "free-wheel coasting," displayed as no arrows flowing on the MFD/MID, is the best use of velocity energy. In this hybrid discussion, "free-wheel coasting" can be considered to be an operating state where velocity energy is being directly converted to "miles" (distance) traveled at a "100% Level of Energy Conversion Efficiency." Staying in "no-arrows free-wheel coasting" for as long as is possible and out of the HSD's energy reclamation-regeneration arrows flowing from the electric motor-generators mode is the best way to optimize and maximize MPG-FE.

Energy reclamation-regeneration in the Prius Hybrid entails conversion of kinetic, Velocity Energy into electrical energy by the motor-generators. This converted kinetic energy is then stored it as chemical energy in the hybrid's NiMH Traction Battery Array. There is an energy conversion loss-penalty at each step of the Kinetic/Velocity Energy-To-Electrical Energy-To-Chemical Energy Conversion Process. The reversal of the Chemical-To-Electrical-To-Kinetic/Velocity Energy Conversion Process to propel the vehicle also has a conversion loss-penalty associated with each step.

Therefore, it is MPG-FE beneficial to "free-wheel coast" using the vehicle's kinetic, Velocity Energy to your best advantage by extending the amount of time you are in "no-arrow free-wheel coasting" while reducing the amount of time you are in one of the other energy reclamation-regeneration modes.

When "no-arrow free-wheel coasting" is not possible or practical, then the next most fuel economy enhancing thing to do to decelerate from a given travel speed is to use "Regenerative Coasting-Braking." The most efficient energy reclamation-regenerative coasting-braking mode is "free-wheel coasting with arrows" displayed on the MFD/MID, while not depressing the brake pedal. In this "Free-Wheeling With Arrows" Regenerative Coasting Mode, reclamation of Velocity Energy-To-Battery-Stored Electrical Energy occurs at an approximately 50% level of Reclamation Efficiency.

When you finally must leave the "Free-Wheeling With Arrows" Regenerative Coasting Mode, and enter the "Brake Pedal Depressed With Arrows" Regenerative Braking Mode to brake, slow down or stop, do so by very lightly depressing the brake pedal a "smidgen." The optimum amount of "smidgen" brake pedal depression is no more than approximately one-quarter inch (¼”) of brake pedal travel. Lightly depressing the brake pedal, by one-quarter inch (¼”±) or less will only engage the "Brake Pedal Depressed With Arrows" Regenerative Braking Mode energy reclamation-regeneration system function, without activating the velocity energy wasting non-regenerative conventional hydraulic friction braking system. Activating the non-regenerative conventional hydraulic friction braking system recovers Zero Energy because it "dumps off" 100% of your kinetic, Velocity Energy as Friction-Heat Energy, which is lost into the air as radiated heat.

By slightly and lightly depressing the brake pedal to where you just "feel" the Motor-Generator (MG) kick in to provide "Brake Pedal Depressed With Arrows" Regenerative Braking, but short of the point that will cause the conventional hydraulic friction brakes to engage, you assure that only the Motor Generator Regenerative Braking System Mode is activated.

MG Regenerative Braking will function to reclaim velocity energy at a ~50±% efficiency until the vehicle finally slows down to a speed of 7 MPH. When the 7 MPH point is reached, the HSD computer automatically engages the regular, conventional non-regenerative hydraulic friction brakes to bring the car to zero speed, and a full stop halt.

By using this tiered, hierarchical approach to coasting, you are becoming "At One With" the Hybrid Synergy Drive's energy use and reclamation system. By slowing down and braking "Hybrid Smart," you aid the Prius energy reclamation Motor-Generator Regenerative Coasting-Braking System in using and converting vehicle velocity kinetic energy into stored electrical energy at the maximum level of conversion efficiency permitted by the HSD System. This reclaimed-stored energy is then available to be used later to propel your vehicle when it goes into the Electric Vehicle (EV-Full Traction Battery Array) Mode, without having to run the gasoline consuming ICE to supply energy to move you down the road.

INCREMENTAL FUEL ECONOMY NOTE: Regular, skillful application of "Hybrid Smart" free-wheel coasting, regenerative coasting and regenerative braking in City, Mixed City-Highway and Highway driving can contribute upwards of an incremental increase of 2± MPG to your Overall Per-Tank-Full Average Fuel Economy .

B. MPG VS. MPH "SWEET SPOT" RANGES: There are three Miles Per Gallon (MPG) vs. Miles Per Hour (MPH) "Sweet Spot" driving speed ranges for the Prius. One is a Low Speed (City) "Sweet Spot" range for "Around Town" City driving. The second is a Mid Speed (City-Highway) "Sweet Spot" range for "Mixed" City-Highway driving. The third is a High Speed (Highway) "Sweet Spot" range for "Open-Road" Interstate/Freeway driving.

Low-To-Mid-To-High Speed "Sweet Spot" MPG-FE Driving Ranges Summary:

"Around Town" City "Sweet Spot" Range: 29-40 MPH (29-45 In 2010-2013 3G Sedan & 2012/13 Prius v).
"Mixed" City-Highway "Sweet Spot" Range: 41-54 MPH (46-59 in 2010-2013 3G & 2012/13 Prius v).
"Open-Road" Interstate/Freeway "Sweet Spot" Range: 55-66 MPH (60-70 In 2010-2013 3G & 2012/13 Prius v).

The Fuel Economy points here are:

These "Sweet Spot" driving speed ranges are "Rule Of Thumb" recommendations. They are based upon trading off tolerable travel and commute time versus optimal fuel economy attainment when having to travel from Point "A" to Point "B" in real-world traffic without impeding or obstructing traffic flow during the transit.

1. Everything else being equal, operating in the Low Speed (City) "Sweet Spot" driving range, between 29 to 40 MPH (29 to 45 in 2010-2013 3G Sedan & 2012/13 Prius v), will facilitate you regularly attaining fuel economies in the low to mid 60s MPG range. This is because, in this speed range, the Hybrid HSD permits you to operate your car in the Electric Vehicle (EV) - Full Battery Array Electric Mode as well as it being the speed range where you can successfully employ the "Pulse and Glide" hypermiling driving technique to further increase incremental instantaneous MPG-FE.

2. Operating in the Mid-Speed (City-Highway) "Sweet Spot" driving range, between 41 and 54 MPH (46 to 59 in 2010-2013 3G Sedan & 2012/13 Prius v), will facilitate getting fuel econmies in the mid to high 50s MPG range, with excursions into the 60s MPG, depending on travel speeds, traffic densities and weather conditions.

3. Operating in the High Speed (Highway) "Sweet Spot" driving range, between 55 and 66 MPH (60 to 70 in 2010-2013 3G Sedan & 2012/13 Prius v), will facilitate you getting low to mid 50s MPG and some times a bit more. High Speed (Highway) Fuel Economy is sensitive to and dependent upon the Target Speed you choose to travel at and whether you employ Electronic Cruise Control (ECC) to control, manage and maintain that Target Travel Speed.

TUTORIAL TECH NOTE: Beginning at around 45-MPH, Aerodynamic Drag starts becoming a noticeable negative contributor to eroding your MPG-FE.

The Aerodynamic Drag - Air Resistance Equation:

R = ½C_dρAv²

R = Drag, Cd = Coefficient of Drag, ρ = Density of Air (fluid), A = Area, v = Velocity

[FYI: Prius Cd = 0.26, Blimp Cd = 0.020~0.025, SUV/Hummer, Cd = 0.45~0.57

Per the equation, Drag, R increases as the square of the Velocity, v of your car through the air (the fluid). Let me try to give you a magnitude kind of feel for the effect of the Velocity-Squared, v²"Speed-Squared," term on increasing the Drag, R.

Consider that increasing your travel velocity, v_tfrom an "Around Town" 45 MPH speed to an "Open-Road" 65 MPH travel speed causes Drag Resistance, R to essentially double. That is, increasing a 45 MPH travel speed by some 40%, to 65± MPH, increases Drag Resistance, R by approximately 210%, or more than double what the Drag Resistance is at 45 MPH.

Aerodynamic Drag Tech Note/Pseudo-Hypermiling Fuel Economy Point:

If your travel schedule, traffic densities, road conditions and the minimum allowed speed limit permit it, opting to travel at speeds of 45 MPH or less will make the negative contribution from Aerodynamic Drag Resistance to eroding your MPG-FE negligible compared to driving a speeds greater than 45 MPH.

C. ROLLING FRICTION AND TIRE SELECTION: Minimizing rolling friction of tires will improve fuel economy. According to testing, switching from regular tires to Low Rolling Resistance (LRR) tires can add 1-2 miles per gallon to your fuel economy. Additionally, keeping regular and LRR tires inflated to or near the maximum allowable "Cold-Ambient" tire pressures specified on their sidewalls will further minimize rolling friction and add even more to fuel economy.

Using LRR tires in combination with Up-Pressuring your tires can contribute an additional 2-7 MPG to your fuel economy. The added fuel economy will depend on the particular rolling resistance friction rating of the tires you have installed on your hybrid, and the "Cold-Ambient" air pressure level to which they were inflated prior to Up-Pressuring them to at or near the maximum allowable "Cold-Ambient" pressure embossed on the tire.

The Fuel Economy point here is:

The specific rolling friction of your tires affects your fuel economy.

Higher Rolling Friction, Lower MPG-FE.

Lower Rolling Friction, Higher MPG-FE.

Inflating the tires on your hybrid to the maximum allowable "Cold-Ambient" air pressure specified on their sidewalls by the tire manufacturer will cut down on their over-the-road rolling friction and, thereby, work to improve overall fuel economy.

As an example, the sidewalls on OEM Goodyear "Integrity" tires mounted on my iconic 2G Prius specify that the tires may be pressurized up to a maximum "Cold-Ambient" air pressure of 44 PSI. I keep my tires inflated to 44 PSI-Front/42 PSI-Rear and reap Higher MPG-FE benefits for every Lower Rolling Friction mile my wheels turn.

I saw an incremental gain of 3± MPG in my Running Average Per-Tank-Full MPG-FE after "Up-Pressuring" the "Cold-Ambient" air pressures of my OEM tires from Toyota recommended 35 PSI-Front/33 PSI-Rear posted on the door post to 44 PSI-Front/42 PSI-Rear. The 3± MPG incremental gain I saw was predicted by, and is in keeping with, the EPA Rule-Of-Thumb that every 1-PSI increase in "Cold" tire air pressure will deliver an incremental gain of from 0.3 to 0.4 MPG in fuel economy.

Using this rule-of-thumb, "Up-Pressuring" the tires on my Prius by 9-PSI should have yielded from 2.7 to 3.6 MPG more in fuel economy. I experienced a gain in fuel economy of ~3 MPG.

OPERATING TECH NOTE: The OEM 185/65-15 Goodyear "Integrity" tires that are "Standard" on the Base and Standard 2G 2004-2009 Prius have a Low Rolling Resistance/Rolling Resistance Coefficient (LRR/RRC) friction rating. The lower the Rolling Resistance Coefficent (RRC), the more efficient of a contributor to high fuel economy is the tire.

Automotive Engineers use the Greek letter μ (“Mu”) as the symbol for tire friction to the road surface. A lower μ supports delivery of better fuel economy. Great care should taken when selecting a replacement tire for the OEM Goodyear "Integrity" tire as well as to the preoperative “Cold” tire pressure PSI preloads you use if you want to keep from taking a multiple-MPG "hit" in your fuel economy. Selecting a replacement tire with high LRR/RRC numbers and using low PSI tire inflation levels can result in a loss of 4-12% (2-7 MPG) in your fuel economy.

INCREMENTAL FUEL ECONOMY NOTE: In my case, if I were to select the wrong replacement tire for my LRR/RRC OEM Goodyear "Integrity" tires, my Overall Per-Tank-Full Average Fuel Economy could drop by 2-7± MPG and bring it down from of 60± MPG to 53-58 MPG-FE.

D. ICE FRICTION AND MOTOR OIL SELECTION: Minimizing the internal friction of the Internal Combustion Engine (ICE) in your hybrid car will work to improve its fuel economy. Toyota specifies 5W30 conventional "Dino" oil in the 2004-2009 2G Prius. Switching from this conventional "Dino" engine motor oil to a 100% Full-Synthetic motor oil will work to lower the internal friction of your Prius hybrid's ICE. The new 2010-2013 3G Prius and 2012/13 Prius v come from the factory with 0W20 Full-Synthetic oil from the factory, so there is no need to switch from "Dino" to Synthetic oil in them to gain this advantage.

Replacing the conventional "100% Dino" motor oil in the ICE of you hybrid with 100% Full Synthetic oil can contribute up to an additional 2%-4% (1 - 2 MPG) to the fuel economy of your hybrid, depending on the particular oil viscosity, brand of Full-Synthetic motor oil you select and the ambient outside air temperatures of the climate in which you are operating (i.e. cool-cold-frigid versus warm-moderate-hot).

Use of Full-Synthetic motor oil with the following viscosity/weights are suggested:

0W20 or 0W30: For operation in cold, frigid Temperature Zone “Sweater/Coat Weather” climate areas where Fall, Winter, Spring temperature lows reach or drop below 41°F/5°C Ambient Outside Air Temperatures [OAT].

5W20 or 5W30: For operation in warmer, moderate Temperature Zone “Room Temperature” climate areas where Fall, Winter, Spring temperature lows normally do not reach or drop below 41°F/5°C Ambient Outside Air Temperatures [OAT].

5W40 or 5W50: For operation in warm to hot Temperature Zone “Desert/Tropical Type” climate areas where outside ambient air temperatures can regularly exceed 100°F.

See Synthetic Oil & Conventional "Dino" Oil SAE Grade Coverage -vs- Ambient Operating Temperatures above.

(Warranty Compliance Note: The Toyota Approved and Warranty Compliant motor oil grade and viscosity called out in the Owners Manual for U.S. Prius Hybrid Vehicles over the full -40°F/-40°C to 104°F/+40°C Ambient Outside Air Temperature [OAT] operating range is ILSAC/SAE 5W30 oil).

OPERATING TECH NOTE: This note applying no matter what kind of oil you choose to use. "Overfilling" the motor oil level in the crank case of the ICE above the "Maximum Fill Level" line (top dot) indicated on the oil dipstick works to cause oil "foaming & sloshing" that adds to rotational load resistance. This added "sloshing" resistance loading on its operation lowers overall fuel efficiency. "Overfilling" can and regularly tends to happen when your car is serviced by dealers and auto service companies who use bulk motor oil dispensing systems. Therefore, even after switching to Full-Synthetic, if you are still operating in a motor oil level "overfilled" condition you likely will see no noticeable additional MPG-FE.

Avid Prius Hypermilers/EcoDrivers claim that the optimum total Full-Synthetic motor oil fill amount is 3.5 quarts of oil. The 3.5 quarts of oil fill level is indicated as approximately 1/8" below the "Full Mark" on the oil dipstick.

Because of warranty considerations and because I live in a climate that is warm all year around, I operated with 5W30 Full-Synthetic motor oil in the crankcase of my Prius 2G/GEN II. I run with the oil level right "On The Money" at and on the "Full" level, top dot mark on the Prius oil dipstick not 1/8" below the "Full Level Mark" as some hypermilers do. I find that 3.7± quarts (3.5 Liters) is required to bring the oil level back to the "Full Level Mark" when replacing-changing both the oil and the standard size Prius oil filter.

The Fuel Economy point here is:

The internal friction of your ICE affects your fuel economy.

Higher Internal Engine Friction, Lower MPG-FE.

Lower Internal Engine Friction, Higher MPG-FE.

Running your hybrid ICE with Full-Synthetic motor oil at the proper fill level will cut down on its internal operating friction and, thereby, work to improve overall fuel economy during operation.

INCREMENTAL FUEL ECONOMY NOTE: After I replaced the conventional "Dino" motor oil in the ICE of my hybrid with 5w30 100% Full-Synthetic motor oil, I saw an incremental increase in Overall Per-Tank-Full Average Fuel Economy of 1.5± MPG.

Running on "Up-Pressured" Low Rolling Resistance tires and using low friction, Full-Synthetic motor oil in you ICE crankcase are two simple, low-cost pre-operative tire and engine friction reducing measures you can take before you even fire up your hybrid fuel-sipper and electro-glide it out of the garage and down your driveway. If you take these tips and apply them, you will see an enhancement of the overall On-The-Road fuel economy delivered to you by your hybrid.

E. HEATING/VENTILATION/AIR CONDITIONING (HVAC) OPERATION: Operating the Heating Ventilation/Air Conditioning (HVAC) system in the Cooling-Heating Mode will erode your MPG-FE. Minimizing operation in the Cooling-Heating Mode will improve fuel economy.

The most fuel efficient HVAC ventilation mode is "Natural Air Conditioning" --- i.e. Fresh Outside Air Ventilation Only. The fuel efficiency "pecking order" preference when using "Natural Air Conditioning" is as follows:

Outside Air Ventilation On - All Windows Up.
Outside Air Ventilation On - Driver's Window slightly lowered ("cracked") and the diagonal opposing right rear back seat passenger window slightly lowered ("cracked") or Front Passenger Window slightly lowered ("cracked") and opposing left rear back seat passenger window slightly lowered ("cracked").
Outside Air Ventilation On - Windows Down In any amount or combination (limit use of this to only when you are traveling at speeds not exceeding 40-45 MPH).

The air conditioning system used in the Prius is electric-powered from the Traction Battery Array rather than being mechanically powered as a belt-driven accessory off the ICE, as is the standard practice in conventionally powered vehicles. So using it “steals” energy directly from the vehicle’s Traction Battery Array that could otherwise be used to propel you down the road for improved MPG-FE.

I observed an approximately 4 to 6± MPG “hit” to my overall average MPG-FE when operating HVAC full-time, compared to when I do not operate it full-time.

The Fuel Economy point here is:

Minimizing operation of the HVAC and associated windshield and rear window defrost functions will help improve your MPG-FE.

OPERATING TECH NOTE: I do not run with the air conditioner set to the "AUTO (ON)” automatic mode. When I do run the A/C, I run it in the “A/C (ON)” manual mode. When driving alone, I function as “my own thermostat” for the cabin temperature. When chauffeuring my June-Bride-For-Life wife around in the Prius "Family Limo," Her Highness “rules” the cabin air temperature by "estrogen edict."

Beside my true love "liking" cool, chilled passenger cabin air to keep her happy and comfy, the Prius Traction Battery Array also "likes" cool cabin air too keep it "happy." The Traction Battery Array in the Prius bleeds air from the passenger cabin through a special air vent located in the area of the rear passenger seat to maintain the battery compartment, which is behind-under the rear seat, in a cool, safe and battery-life-extending thermal operating temperature.

NOTE OF CAUTION: Impeded air flow to the High Voltage (H.V.)Traction Batterty can contribute to and bring about a premature, thermally induced Traction Battery Array failure.Take care to never block or obstruct the Battery Compartment Air Intake Ventilation Grille or Venting OPening in the rear passenger area of the GEN II (2G), GEN III (3G), Prius v, or Prius c with objects, plastic bags, accumulation of pet hair or the like. In the iconic 2G and Next-Gen 3G, this Battery Compartment Air Intake Vent is located on the right side of the rear passenger seat by the door jamb. The Prius v ("vee") and c (cee) does not use this same venting design, and so does not have a grille covered vent associated with the rearseat periphery that can be easily obstructed to block airflow into ventilation ports for the H.V. Traction Battery.

When I do run the HVAC in the cooling mode, I manually cycle the A/C On & Off, as determined by the aforementioned, "Joe, it is getting hot now, turn the A/C ‘ON’ or Joe, I am getting cold, turn the A/C ‘OFF’” bio-thermostat, my beautiful wife. By using this driver-controlled “Manual A/C ON” practice of mine as much as possible, I only run/turn on the A/C when the ICE is running or is caused to run by the HSD. I try never to run the A/C when I am running in the Electric Vehicle (EV) Mode to keep from “robbing” energy from the Traction Battery Array that would otherwise be used to propel the car down the road for increased MPG-FE.

I call my practice of manually operating the A/C only when the ICE is running, my “Free Energy Cooling Mode.” I use the term “Free Energy” because since the HSD is causing the ICE to run and consume fuel, any way, I feel I might as well have the A/C turned on to scavenge a bit of energy-power off the ICE-HSD and produce cold air to cool the cabin and traction battery, thereby, giving me a “Free Energy Cooling Ride.”

Of course, there is no such thing as “Free Energy Lunch,” but I consider it a “Free Energy ‘Lunch’ Cooling Ride” because the ICE is already being caused by the HSD to run and consume fuel to generate electrical energy, and I am just "Freely" bleeding some of it off to cool the cabin.

INCREMENTAL FUEL ECONOMY NOTE: I find that by utilizing my particular driver-controlled Manual A/C ON-OFF Free Energy ‘Lunch’ Cooling Mode Cycling practice to run the A/C, rather than running the A/C running in AUTO A/C Mode Full-Time, my Overall Per-Tank-Full Average Fuel Economy A/C “Energy Hit” is reduced from a minus 4± MPG [With Full-Time AUTO A/C Use] down to a minus 3± MPG [With Free Energy A/C Cycling].

F. CONTROLLING THE HYBRID SYNERGY DRIVE (HSD):

The foot throttle pedal on the Prius is the driver-operator's primary control of the Prius Hybrid Synergy Drive system. Learning how to use the throttle pedal to keep the Prius in its lowest available fuel consumption mode for a given driving condition will pay big incremental fuel economy dividends.

The Fuel Economy point here is:

To control your Hybrid for maximum fuel economy you must learn how to intelligently, and deftly use your foot to control the foot throttle in combination with observing the Hybrid Operating Mode on the Multi-Function Display (MFD) LED Monitor, in the 2004-2009 Prius, only the Multi-Information Display (MID) Panel in the 2009½ (2010)―2013 Prius, and both a Multi-Function Display (MFD) LED Monitor and Multi-Function Instrument Display (MID) panel in the 2012/13 Prius v ("Vee").

TECH NOTE: The 2009½ (2010)―2013 3G Prius Sedan Hatchback did away with using a large, easy-to-read, full-color, high resolution Multi-Function Display (MFD) LED Monitor to display ENERGY and CONSUMPTION. Whereas, the new, 3G HSD-based 2012 Prius v Station Wagon incorporated using a large, easy-to-read, full-color, high resolution Multi-Function Display (MFD) LED Monitor like is used in the iconic GEN II 2G Sedan Hatchback to display ENERGY and CONSUMPTION information, supplemented by a specialty fuel economy consumption Hybrid System Indicator display on the left side (U.S./North America) Multi-Information Display (MID) Panel.

Only for the 3G Sedan Hatchback, has the Energy and Consumption readouts been moved up to a smaller, less-easy-to-read, mono-colored, blue-green plus red Liquid Crystal instrument panel cluster display strip call the Multi-Information Display (MID).

As a result, color references to the ORANGE-RED [Gasoline Being Consumed/Used By ICE], BLUE-GREEN [Energy Being Regenerated/Recovered], YELLOW [Stored Traction Battery Charge-Energy Being Consumed To Propel Vehicle], colored arrows and BLACK [Zero Energy Being Consumed/Generated] color lines in the discussions that follow, only apply to the 2004-2009 2G Prius hybrids, and not the 2010-2013 sedan hatchback model. However, the functions of the Zero Energy Being Consumed/Generated lines and Energy Being Regenerated/Recovered, Stored Traction Battery Charge-Energy Being Consumed To Propel Vehicle and Gasoline Being Consumed/Used By ICE energy flow arrows displayed on the 2010-2013’s MID remains the same.

The Prius v Station Wagon displays different colored ENERGY SCREEN arrows-lines on its MFD LED Monitor Screen, compared to the colors used on iconic Prius 2G. The "Vee" also provides instantaneous fuel consumption and running average fuel economy on the MID along with a Full-Color unique ECO/EV/POWER display on the left side of the MID to aid the driver in driving "Hybrid $mart - In The Zone."

The Human Factors Engineers at Toyota get an A+ from me on the wonderful job they did with the MFD/MID design solution installed on the Prius v Station Wagon.

Zero Energy Being Consumed/Generated Lines [BLACK In 2G] or Energy Being Regenerated/Recovered Arrows [BLUE-GREEN In 2G] or Stored Traction Battery Energy-Charge Being Consumed To Propel Vehicle Arrows [YELLOW In 2G] energy flowing on the MFD are "GOOD" FOR FUEL ECONOMY. Whereas, Gasoline Being Consumed/Used By ICE Arrows [ORANGE-RED In 2G] flowing on the MFD/MID are "BAD" FOR FUEL ECONOMY.

Simply put, to maximize MPG-FE it is best to keep to operating on the zero energy being consumed end of the energy use hierarchy.

Here is the Prius Hybrid Vehicle Minimum Energy Use/Max Fuel Economy Mode Hierarchy:

1. "Free-Wheeling" Pure Coasting Mode: 2G – All Black Lines on MFD. 3G – Glide Zone on HSI. "Vee" - ECO Leaf Symbol & ECO Light Illuminated on HSI with No "Green or White" Lines or flickering between "Green & White" Lines on the HSI MID. No Arrows on MFD Energy Screen, No Lines on ECO/EV/PWR HSI & 99.9 iMPG on MID. No Motor Fuel Being Burned or Traction Battery Electricity Being Used. No Electricity Being Generated. THIS IS THE MOST FUEL EFFICIENT, MISERLY "FUEL-SIPPING," ENERGY CONSUMING MODE!

2. "Free-Wheeling" Regenerative Coasting Mode: 2G – Blue-Green Arrows on MFD. 3G – CHG Zone On HSI. "Vee" – ECO Leaf Symbol & ECO Light Illuminated on HSI & MID. "Regeneration" Arrows Flowing on MFD, One (1) White Line Illuminated in CHG Zone on HSI & 99.9 iMPG on MID. Reclaiming Energy Via MGen1. Traction Battery Being Charged.

3. Regenerative Braking Mode: Brake Pedal Lightly-Slightly Depressed. 2G – Blue-Green Arrows on MFD. 3G – CHG Zone on HSI. "Vee" – ECO Leaf Symbol & ECO Light Illuminated on HSI & MID. "Regeneration" Arrows Flowing on MFD, Two (2) or Three (3) White Lines Illuminated in CHG Zone on HSI & 99.9 iMPG on MID. Reclaiming Energy Via Both MGen1/MGen2. Traction Battery Being Charged.

4. EV-Electric Vehicle Mode: 2G – All Yellow Arrows. 3G – ECO Zone n HSI. "Vee" – Both EV Car & ECO Leaf Symbols on HSI Display With ECO Light Illuminated on MID. Lower-Half "GREEN LINES" Illuminated In EV Zone on HSI & 99.9 on iMPG on MID. Arrows From Battery To Wheels on MFD Monitor. Running Only On Electricity & Discharging Traction Battery.

5. ICE ON Consuming Fuel & Charging Traction Battery Mode: 2G – Orange-Red Arrows To Wheels With Steady Yellow Arrows Into Battery. 3G – Operating in Right Half of Bar On HSI. "Vee" – ECO LIght OFF. Operating at or Around the "GREEN LINES" Mid-To-High Point of the ECO/EV/PWR Display on HSI & Less Then 99.9 iMPG Displayed on MID. Propulsion Energy From Gasoline Engine To Wheels Along With Steady Arrows Showing on MFD Monitor Going Into & Charging Traction Battery.

6. ICE ON Consuming Fuel & EV-Electric Vehicle Boost Mode: 2G – Orange-Red Arrows Going From Engine To Wheels Along With Occasional Yellow Arrow "Spurts-Flashes" of Battery-To-Wheels Power Boost Shown by Discharging Yellow Arrows Flowing From Traction Battery Into MGen/Wheels. 3G – Operating on Far Right Half Of HSI with Some Amount Of "RED BAR" Extending into "PWR ZONE." Engine-Powered Electric Charging Arrows Flowing Into & Charging Traction Battery. "Vee" – ECO & EV Symbols on HSI NOT Illuminated. ECO Light On MID OFF. Operating On Upper "RED LINES" PWR Section of ECO/EV/PWR MID HSI Display --- The "RED LINE AREA IN POWER ZONE ILLUMINATED," Engine-Powered Electric Charging Arrows Flowing Into & Charging Traction Battery on MFD & Much Less Then 99.9 iMPG Displayed on MID. THIS IS THE MOST INEFFICIENT, "FUEL THIRSTY" ENERGY CONSUMPTION OPERATING MODE!

THERE IS NO “FREE ENERGY LUNCH.”

The more you drive on the 1, 2, 3 end of the Energy Use/Max Fuel Economy Mode Hierarchy, rather than on the 4, 5, 6 end of it, the less gasoline you will consume and more “FREE ENERGY” Traction Battery charging you will reclaim-regenerate. Less fuel used and more “FREE REGENERATIVE ENERGY” reclaimed, equates to BETTER FUEL ECONOMY.

The more you drive on the 4, 5, 6 end end of the Energy Use/Max Fuel Economy Mode Hierarchy, rather than on the 1, 2, 3 end of it, the more gasoline you will consume and more stored Traction Battery “ENERGY” you will use. More fuel burned and more Traction Battery “ENERGY” used, equates to WORSE FUEL ECONOMY.

With specific focus on the braking, brake pedal application functions, the first preference is to anticipate having to come to a “Full Stop” well ahead of the stopping point, and go into and stay in the "Free-Wheeling" Regenerative Coasting Mode for as long as you can. This mode delivers regenerative braking via the MGen 1 charging the Traction Battery without touching the brake pedal.

When you want or need to get more braking-slowing than this "Free-Wheeling" Regenerative Mode gives you, just lightly depress the brake pedal. This will put you into the Regenerative Braking Mode switching in MGen 2 to assist in Regenerative Braking-Slowing as MGen 2 also works to charge the Traction Battery. Ideally, you can stay in this Regenerative Braking Mode until you slow to 7 MPH (11 KPH) where the friction brakes (zero energy reclaimed) are automatically engaged by the Hybrid Synergy Drive controller.

Pressing the brake pedal beyond just a light pedal application, puts you in Friction Braking, which reclaims, captures ZERO ENERGY because the velocity energy is lost and dumped off as friction heat from using the Friction Brakes.

A "HYBRID $MART" ENERGY USE EXAMPLE FOR CLIMBING HILLS: Using foot throttle pedal position and Multi-Function Display to keep the Prius operating on its Minimum Fuel Consumption “$weet $pot” when negotiating inclines and hills.

Slight Uphill: Throttle pedal positioned to keep iMPG = iMPH.
Moderate Uphill: Throttle pedal positioned to keep iMPG = 0.8 times iMPH.
Significant Uphill: Maintain iMPG as close as possible to 0.8 times iMPH during climb.
Moderate Downhill: Feather back on throttle to keep iMPG = 1.3 to 1.5 times iMPH.
Significant Downhill: Use/Enter “Warp Stealth” Mode by feathering throttle pedal to achieve, and keep an All Yellow Arrows (Battery Only) condition on CONSUMPTION Display.

G. "ICE" COLD START/RESTART: The following discussion on the Cold Start/Restart characteristics and behavior of the HSD & ICE assumes a nominal Operating Temperature Range (OTR) environment for the hybrid car that runs from 41°F/5°C-To-104°F/40°C.

In the 2004-2009 2G Prius, the first five (5) or so minutes on Initial Cold Start-Up, and for a minimum of a minute (57-seconds minimum) or so after each Restart after being warmed up, the HSD Computer causes the ICE to run in a Rich-Burn Fuel Mode (i.e. Choke-On/Throttle-On Mode) rather than in a Lean-Burn Fuel Mode (Choke-Off, Economy Mode). [NOTE: In the 2009½ (2010)-2013 3G Sedan and 2012/13 v (“vee”) Station Wagon this five minute warm-up time is shortened somewhat because of the new exhaust heat exchange-recovery system in the 2009½ (2010)-2013 3G Sedan Hatchback and 2012/13 v (“vee”) Station Wagon].

The gasoline engine (ICE) will run in this “Rich Burn, Choke-On/Throttle-On Mode” until the ICE and Catalytic Converter warm/re-warm up to their specified “normal” operating temperatures. This Initial Cold Start-Up/Restart, Rich-Burn period, which can run from 57-seconds on a "warm" engine to five (5) or more minutes on a "cold" engine, is one of the most inefficient fuel consumption times for Gas-Electric Hybrid system operation.

Fuel economy focused Prius and other hybrid owner-operators, especially those operating in colder, Temperate Zone climates, install after-market Engine Block Heaters (EBH) into the ICEs of their cars so their Initial Cold Start-Ups begin with the ICE block, motor oil and engine coolant fluid already in a pre-warmed state.

As an additional aid to accelerating engine compartment warm-up and keeping and running the ICE in the "Sweet Spot" temperature range that delivers Max-MPG-FE, some drivers operating in frigid Northern Temperate Zone environments (≤ 41°F/5°C Ambient Outside Air Temperatures [OAT]) partially block some of the space in part of the Prius front grille air intake louvers with cylindrical foam insulation like that used to insulate hot water pipes in your home.

NOTE OF CAUTION: Operating the ICE with the front air intake grille louvers partially or completely blocked off with foam insulation when Ambient Outside Air Temperatures (O.A.T.) exceed 41°F/5°C may result in harmful and damaging overheating of the ICE and propulsion components. Grille Louver Blocking should only be done when outside ambient temperatures will remain at or below 41°F/5°C throughout the day. Leaving engine compartment ventilation louver blocking material in the grille when O.A.T. temperatures rise above 41°F/5°C may result in damage to the engine, inverter and transmission.

People who venture to use grille louver blocking above 41°F/5°C usually have after-market ScanGauge II or similar add-on instrumentation installed so they can monitor the temperatures of the ICE and key propulsion components to keep them from overheating and being damaged.

Using EBH and foam insulation can shorten the length of the five (5) minutes warm-up period by the last approximately 4-minutes and 3-seconds of the Initial Cold Start-Up nominal 5± minute warm-up period that would normally extend past the HSD software mandated 57-seconds minimum warm-up period if the engine had not already been pre-warmed. The positive incremental MPG-FE benefits of EBH pre-warming of the ICE comes, in best-case, from only needing to run the ICE in the Rich-Burn, Choke-On/Throttle-On Mode for the HSD mandated 57-seconds minimum instead of the mandated 57-seconds plus the additional approximately 4-minutes and 3-seconds or more of the typical Initial Cold Start-Up nominal 5± minute warm-up period without EBH pre-heating.

The Fuel Economy points here are:

1. Learning to operate the foot throttle pedal with a deft, feather-light touch during the first few minutes of operation after Start-Up, until the gasoline engine warms/re-warms up to normal operating temperatures, and transitions into the more economical Lean-Burn, High-MPG Mode, will deliver big fuel economy benefits.

During Start-Up/Warm-Up, until the ICE warms/re-warms up, the gasoline powered ICE operates in a "thirsty," high fuel consuming Rich-Burn, "Choke On" Mode. Therefore, delicate and judicious operation of the foot throttle pedal during this critical warming/re-warming period will aid in minimizing unnecessary consumption of additional fuel economy "robbing" fuel.

Using a "Heavy Gas Throttle Pedal Foot" during this initial Start-Up/Warm-Up period, only injects unneeded and unusable fuel into the ICE. This “dumped in” added fuel ends up exiting as unburned, raw gasoline out through your exhaust pipe without adding any propulsion power. A driver "Horsing" the gas throttle during this Start-Up/Warm-Up, Rich-Burn "Choke On" period, only "adds insult to injury" regarding fuel economy. The unusable, additional fuel injected into the ICE only serves to erode fuel economy further because the ICE is already running in a "thirsty," high fuel consuming Rich-Burn Mode.

GAS SAVING "TRICK": Here is a "Trick" to minimize having the ICE consume a wasteful additional amount of fuel during its Start-Up/Warm-Up period of operation. During Start-Up/Warm-Up, it is best to get up to and keep your travel speed at no less the 15 MPH, preferably at or around 25 MPH, by using only the automatic “Idle Speed” fuel metering “Choke On” setting selected by the Hybrid Synergy Drive (HSD) Control System. That is, let the Prius move along at the throttle setting automatically set by the HSD while you refrain from using any additional application-depression of the foot throttle pedal during this “fuel thirsty” warm-up/re-warm up period. If you do this, you will be rewarded with even greater incremental fuel savings, thereby, enabling your Prius to deliver improved overall Per-Tank-Full EPA MPG Fuel Economy to you.

FWIW FYI: When this sailor-technologist "weighs anchor," and shoves off from his residential "slip" in his Prius hybrid, I do my best to "steam" down the "channel" in my neighborhood at a “NO WAKE” Minimum Fuel Consumption High-MPG Idle Speed. This “Idle Speed” is the nominal speed that results from the automatic Rich-Burn Mode Warm-Up/“Choke" fuel consumption metering throttle setting selected by the HSD control software during the few minutes of ICE Warm-Up operation.

Depending on the Ambient Outside Air Temperature, this “NO WAKE” High-MPG, HSD-Selected Idle Speed usually moves me along at or about 15-25± MPH with the MFD (2G)/HSI-MID (for 3G, "vee," c) initially displaying a ~10-30± instantaneous miles per gallon (iMPG) reading. The iMPG reading at “Idle The incremental fuel savings bonus from utilizing this "NO WAKE" High-MPG Idle Speed practice are reflected in the improved, overall Per-Tank-Full MPG averages I log, which significantly exceed the Official EPA Fuel Economy Estimate numbers. Speed” gradually increases as the ICE warms up to and through the nominal 158°F/70°C operating temperature Toyota has Spec'ed for the Prius HSD before it can go into the desired high fuel efficiency Stage 4 (S4) hybrid operating mode.

2. Making one Grand Tour Shopping-Errand Running Trip rather than separate, multiple individual shopping trips will help improve overall fuel economy because it diminishes the fuel-consumption inefficiency effect of the ICE having to cycle through the Cold Start/Restart Rich-Burn Mode multiple times.

ERRAND RUNNING TIP: MPG-FE conscious Psuedo-Hypermiler owner-drivers running quick ≤ 2-minute Errands or brief duration stops push the PARK BUTTON and engage the PARKING BRAKE, but leave the HSD/ICE powered up rather than hitting the POWER BUTTON to power them down. This keeps their Prius Hybrid operating in the “Warmed Up/In Lean-Burn Mode” S4-Mode.

For errand running stops of ≤ 2-minutes or so in duration, like stopping to run into check your post office box, drop-off/pick-up at the cleaners, quick Fast-Food drive-through pick-up, etcetera, the ICE will consume less gasoline if left with the “PARKING BRAKE ENGAGED,” transmission in “PARK” and “Powered Up & Idling In Lean-Burn Mode S4-Mode" rather than “Shutting It Off/Powering It Down.”

“Shutting It Off/Powering It Down” and then quickly restarting causes the HSD/ICE to go through the mandatory 57-second “Rich-Burn/Throttle-On Start-Up/Restart Mode” and S1, S2, S3 to S4 modes sequence Toyota has imposed. This forces the engine to run and consume fuel even if the car has a fully charged traction battery and is already warmed up and at operating temperatures.

This “Leave It Running” incremental saving in fuel consumption can be most conveniently and safely accomplished when a spouse, friend, significant other or other licensed driver is with you in the car as either a driver or passenger. That way one of you can dash off to run quick, ≤ 2-minutes errands while the other person stays in the vehicle with the Smart Key to “baby sit” the Prius Hybrid Synergy Drive System while it is operating in the“Powered Up/Idling In Lean-Burn Mode.”

3. This temperature sensing, computer controlled Rich-Burn-To-Lean-Burn operating characteristic is why the Prius Hybrid delivers the best fuel economy in warmer climates, like Deep-South Dixieland, Florida, Hawaii, AZ, NM, NV, SoCal and TX, where the daytime outside ambient air temperatures (OATs) are in the 60s to 80s (Fahrenheit) range most of the time. Warm outside ambient air temperatures serve to shorten the duration of the warm-up period and length of the "thirsty" Initial Start/Restart Rich-Burn Mode of fuel consumption.

INCREMENTAL FUEL ECONOMY NOTES: 1. By consolidating Shopping Trips/Errand Running [0.5± MPG gain] and employing the Quick - Less Than Equal To - 2-Minute Errand Running MPG-FE Enhancing Technique of leaving the ICE/HSD Powered Up & Idling rather than Shutting It Off/Powering It Down to run ≤ 2-Minute Errands [0.5± MPG gain] can deliver upwards of a combined total gain of 1± MPG in OverallPer-Tank-Full Average MPG-FE. 2. In frigid operating climates, pre-warming the ICE block using an EBH in combination with partially blocking some or most of the space in part of the Prius front grille louvers with cylindrical foam pipe insulation has been reported to add 4-10 MPG-FE to Overall Per-Tank-Full Average Fuel Economy compared to Cold Weather Operation without using EBH & Grille Louver Blocking.

CAUTION: Grille Blocking can be safely used only if maximum daytime ambient O.A.T.s are less than or equal to 41°F/5°C.

H. "INFINITE" INSTANTANEOUS MPG-FE: Whenever the Gasoline Engine (ICE) IS NOT RUNNING and you are moving down the road, you are getting over 99.9+ MPG (i.e. "Infinite" Instantaneous MPG). When the ICE IS RUNNING and you are moving, you are getting ~30-35 MPG.

The Fuel Economy points here are:

1. Anytime the internal combustion gasoline engine is not running and you are moving down the road, you are getting "Infinite" Instantaneous Miles Per Gallon Fuel Economy. This "Infinite" Miles Per Gallon is displayed as 99.9 MPG on the Multi-Function Display (MFD) or Multi-Information Display (MID), as applicable. Conversely, if the ICE is running constantly, as the HSD may cause it to do in extremely cold, frigid winter weather operating conditions, the Instantaneous Miles Per Gallon Fuel Economy will converge on the 30-35 MPG fuel economy inherent to the ICE itself.

30-35 MPG (WORST) ---- YOU ARE DRIVING SOMEWHERE IN HERE ---- 99.9+ MPG (BEST)

2. Learn to use a feather-light touch on the foot throttle pedal to keep your hybrid automobile running down the road with the ICE off, and in the Electric Vehicle (EV) Full-Traction Battery Mode [YELLOW >>>>> ARROWS On 2G] or Regeneratively Coasting-Recharging Traction Battery Array Mode [BLUE-GREEN >>>> ARROWS On 2G] or with Zero Energy Being Consumed Mode [BLACK >>>>> ARROWS/LINES On 2G].

Your challenge, if achieving "Stellar," Ultra-High Fuel Economy Per-Tank-Full numbers is your goal, is to control the Hybrid Synergy Drive to have your Prius operating at the 99.9+ "Infinite" Instantaneous Miles Per Gallon Fuel Economy "Fuel Sipping" end of the fuel-energy consumption spectrum much more than it does at the 30-35 MPG "Fuel Thirsty" end of it.

I. "ELECTRO-GLIDING"/FULL-TRACTION BATTERY ARRAY "EV" MODE: In practical day-to-day driving-commuting application, the most fuel effeicient "Around Town" City Driving speeds that will yield the largest fuel economy dividends for the Prius 2G/"Cee") are over the speed range between 29 and 40 miles per hour, and between 30 and 44 miles per hour for the 3G/"Vee." Over this 29-40 MPH (2G/"Cee")/30-44 MPH (3G/"Vee") speed range, running in the "Electric Only" Full Hybrid Traction Battery Array, Electric Vehicle (EV) Mode whenever the battery is charged at or above the 60% Charge "Six (6) Blue Bars" Point on the 2G MFD (6 "Plain" Bars on 3G/"Vee") supplemented with "Pulse and Glide" driving techniques will assist you in your pursuit of "stellar" MPG-FE numbers. In my personal driving experience, operation between 29 and 40

(2G/"Cee") and 30 and 44 (3G/"Vee") MPH, usually will deliver fuel economy numbers at, on or around the old 60 MPG-FE Pre-2008 EPA "CITY" estimate numbers for the iconic 2G Prius and in the 50s for the 3G/"Vee."

The Hybrid Synergy Drive (HSD) system, as installed in the Prius, has an idiosyncratic technical "quirk." When operating solely off traction battery power, this "techno-quirk" causes instantaneous miles per gallon (iMPG) to drop by ~8% as the speed of the car transitions from 40+ miles per hour through 41 to 42 miles per hour for the 2G, and 43+ miles per hour through 44 to 45 miles per hour for the 3G/"Vee."

In the Full-Traction Battery Array (EV) Mode, at a point just over 40+ MPH (approximately 40.5 MPH or so, i.e. 41± MPH) for the 2G, and 43+ MPH (approximately 43.5 MPH or so, i.e. 44± MPH) for the 3G/"Vee," the HSD control system causes the ICE to begin transitioning into full mechanical engagement with the HSD drive system. The HSD causes the ICE to begin to proportionally "freewheel" at ≤ 960 RPM to protect Motor Generator 1 (MG1), thereby, ensuring it does not over-speed. During this protective "freewheeling" mode the ICE is not running, consuming fuel or providing any propulsion power, but adds a mechanical "drag" on the HSD propulsion system.

The published, official ICE "freewheeling" transition point speed for the 2G is 42 MPH (67.6 kmPH), and 45 MPH (72.4 kmPH) for the 3G/"Vee." However, in practice, anytime the indicated speed on my Prius speedometer starts to creep above 40 MPH (2G)/44 MPH (3G/"Vee"), I will usually "feel" a slight "lunge/flump" as the ICE comes into full engagement with the HSD drive system and starts "freewheeling."

Therefore, when driving in the "Electric Only," Electric Vehicle (EV) - Full Traction Battery Array Mode at or above 41 MPH (2G)/44 MPH (3G/"Vee"), you have the added "Dead Weight" load mechanical burden of the freewheeling, rotating non-functioning ICE loading down the hybrid propulsion drive system that cuts into and degrades fuel economy.

The Fuel Economy point here is:

When you are traveling "Around Town" on streets or roads with speed zones in the Low Speed (City) "Sweet Spot" range and choose to run in the "Electric Only" Full-Traction Battery (EV) Mode, be sure to keep your speed at or below the "magic" 40 MPH (2G)/43 MPH (3G/"Vee") transition point whenever you can. Doing so will keep the ICE from engaging and start "freewheeling" to put a rotational "Dead Weight" mechanical drag on the HSD drive system to degrade your MPG-FE.

Compared to the instantaneous MPG delivered for the iconic 2G driving at 40 MPH in the "Electric Only" Full-Traction Battery (EV) Mode without the added load of a "freewheeling" non-functioning ICE, instantaneous MPG will be lowered by upwards of 8% when driving in the "Electric Only" EV-Battery Mode at speeds of 41 MPH and above because the added load of an engaged, freewheeling and non-functioning ICE is dragging on the HSD drive system. The same thing applies for the 3G/"Vee" at 43 MPH and 44 MPH points.

OPERATING TECH NOTE: Consider this typical "Around Town" driving scenario with you motoring down the road in a 2004-2009 Model Year 2G in a 45 MPH speed zone with 6-Bars or more showing on the MFD as your SOC (State Of Charge - Traction Battery). In this situation, do not cruise at the 45 MPH speed limit if you want to improve incremental instananeous MPG-FE. Why, you ask? Because just by choosing to travel with your speed at or below the "magic" 40 MPH point and running in the EV-Full Battery Mode rather than going 1-4 MPH faster at 41-45 MPH will serve to improve your instantaneous fuel economy by some 8±% or 5± MPG. This is because when running in the EV-Mode at ≤ 40 MPH the ICE will stay off, stationary and disengaged from the propulsion drive system.

"Hybrid Smart" 2G drivers try to operate in this "Around Town" EV-Mode at ≤ 40 MPH whenever they can because it works to maximize their incremental iMPG as compared to when they drive in the same "Electric Only" EV-Mode at or above 41 MPH where the HSD forces the ICE to be engaged and "freewheel."

INCREMENTAL FUEL ECONOMY NOTE: The added rotational "Dead-Weight" mechanical load of the "Freewheeling" ICE degrades Incremental Instantaneous Fuel Economy by some 6-8% or approximately 3.5-5 MPG.

J. ECC USE ON "OPEN ROAD" AND DASH (pULSE) & COAST (gLIDE) "SWEET SPOT": When working to optimize highway travel speed against fuel consumption, the best and most reasonable recommended "Open Road-Interstate/Freeway" Highway Driving speed range is over the range 55-66 (71 3G/"Vee") MPH.

Whenever "Open Road" highway terrain, weather, traffic densities and highway driving conditions permit it and are favorable, I employ a high-speed ( ≥41 MPH) version of the low-speed (< 41 MPH/< 45 MPH) "Pulse and Glide" driving technique. I call this high-speed version of "Pulse and Glide" driving the "Dash (pULSE) and Coast (gLIDE)" technique. I generally use this fuel saving "Dash and Coast" technique over the range 55 (Lower End) to 66 (Target Speed) to 70 (Top Of Range) MPH for 2G/"Cee"), and 60 (Lower End) to 66 (Target Speed) to 75 (Top Of Range) for 3G/"Vee."

High-speed highway driving that integrates intermittent use of "Dash and Coast" with ECC (Cruise Speed set to 66 MPH on 2G/"Cee") and 71 on 3G/"Vee") and running with Outside Air - ON and Air-Conditioner/Heater - OFF usually delivers fuel economy numbers to me over a range of 52-58 miles per gallon with occasional MPG-FE excursions into the low to mid 60s. Using "Dash and Coast" to help deliver such "stellar" MPG-FE numbers does require a bit of "Dash and Coast Driving Work."

INCREMENTAL FUEL ECONOMY NOTE: Opportunistic use of the Low-Speed ( < 41 MPH) Pulse & Glide and High-Speed ( ≥41 MPH) Dash and Coast driving techniques in Mixed City/Highway byway and highway driving can deliver an incremental increase in Overall Per-Tank-Full Average Fuel Economy of 2± MPG.

If you would rather do some "Easy Rider" cruising rather than having to "Work At Driving" to squeeze out a few extra incremental MPGs of fuel economy from your "fuel-sipper," try using 66 MPH as your "Interstate/Freeway" travel cruise speed. Just set the Electronic Cruise Control (ECC) at 66 MPH (2G/"Cee") )/71 3G/"Vee"), which is the top-end of the "Open Road" Interstate/Freeway Driving MPG-FE "Sweet Spot" Range, and then let Toyota's Software "Troops" and their Hybrid Synergy Drive fuel economy control subsystem do the fuel saving "Work" for you.

With the HSD set at an ECC controlled 66 MPH for 2G/"Cee") (71 MPH for 3G/"Vee") cruise set-speed, and depending on the weather, wind and whether your "Hot Mama" Prius-Borg Queen has issued a "Prius-Borg Drone, Turn On The Air Conditioner" edict to keep Her Highness Cool, Comfortable & Happy, the Prius 2G/GEN II, 3G GEN III, "Vee" and "Cee" will regularly deliver 50+ MPG-FE to you as you roll over-the-road on your Up-Pressured, Low Rolling Resistance OEM tires at more than a mile-per-minute.

When The Prius-Borg Queen Is Happy

Her Prius-Drone "Chauffeur" Is Happy

I use and recommend using a 66 MPH Electronic Cruise Control (ECC) Set-Speed for driving the GEN II/2G because 66 MPH is the top-end of the "Open Road" MPG-FE "$weet $pot" range for "Interstate/Freeway" travel in a 2G & "Cee.", and use the 71 MPG-FE "$weet $pot" for the 3G & "Vee." I overlay this ECC controlled travel cruise speed with use of anticipatory manual foot throttle pedal override of the ECC to accelerate the Prius in anticipation of approaching hills or crossroad pass over ramp inclines (i.e. I use Driving With Load (DWL)).

I find that using this anticipatory "smart" manual throttle override for hills, up-slopes and overpasses incrementally adds to average overall trip fuel economy by preventing wasteful "dumb" ECC induced fuel surges that would occur at the foot of hills/inclines because the "dumb" ECC is not "smart" enough to anticipate the throttle settings required to increase the speed-power needed to climb hills/inclines ahead of time.

Application of Electronic Cruise Control (ECC) in this way in driving the iconic Second Generation (2G/GEN II) Prius on long distance over-the-road trips, has been shown to regularly deliver 53 to 56 MPG for me (measured by both the multiple-tank-refill method and the MFD MPG calculation display).

The Fuel Economy points here are:

1. When traveling at "Interstate/Freeway" Highway Driving speeds, remember that the High-Speed Fuel Economy "$weet $pot" Range of Interstate driving speeds versus fuel consumption is over the range 55 to 66 for the GEN II/2G. As the above "Fuel Economy Expectations For Pseudo-Hypermilers" graph shows, traveling at cruise speeds below 55 MPH in the 2G will give incrementally better gas mileage, but will cause you to arrive at your destination somewhat later. Whereas, cruise speeds above 66 MPH (2G/"Cee") 71 MPH (3G/"Vee") "$weet $pot" cruise speed will start to consume an inordinate amount of fuel for the extra incremental speed-time gained, and drop you below the EPA "Highway" MPG-FE Estimate for each particular Prius type.

2. Driving using an Electronic Cruise Control (ECC) Set-Speed of 66 MPH (for 2G/"Cee") with time efficient stops for fuel, food and comfort breaks, like I do, usually delivers an average total trip travel speed of at least 60± MPH, which is a mile-per-minute. Interspersing "Dash (pULSE) and Coast (gLIDE)" around a 66 MPH Target Speed, into such "Open-Road" driving, will regularly deliver 51± MPG "actuals" or more with a respectable mile-per-minute, 60± MPH, average Point "A" to Point "B" trip speed.

As an example, let us assume $3.00 per gallon gasoline, a 360 mile "Open Road" Trip in a GEN II/2G, 99.5% which is Interstate/Freeway driving.

50 MPH/55.5 MPG >>> 360 Miles >>> 7.2 Hours/6.5 Gallons/$26.00

55 MPH/54.0 MPG >>> 360 Miles >>> 6.6 Hours/6.6 Gallons/$26.40

60 MPH/53.0 MPG >>> 360 Miles >>> 6.0 Hours/6.8 Gallons/$27.20

66 MPH/51.0 MPG >>> 360 Miles >>> 5.5 Hours/7.0 Gallons/$28.00

70 MPH/47.5 MPG >>> 360 Miles >>> 5.1 Hours/7.6 Gallons/$30.40

75 MPH/44.2 MPG >>> 360 Miles >>> 4.8 Hours/8.1 Gallons/$32.40

80 MPH/40.0 MPG >>> 360 Miles >>> 4.5 Hours/9.0 Gallons/$36.00

Rather then traveling at my recommended let us assume you decide to travel the 360 miles at a cruise set-speed of 80 MPH. 80 MPH is the 70-75 MPH maximum legal speed on most Interstate, limited access type highways in the U.S. 66 MPH "$weet $pot" Electronic Cruise Control Set-Speed, with the 5-10 MPH "Grace Speed" many drivers claim "the cops will give you" over the maximum speed limit added to it (I am not sure this "the cops will give you" is true anymore). Traveling at 80 MPH over 360-miles would cost you $6.00 (~2-gallons) more in gasoline and take 60 minutes less in on-highway travel time compared to traveling at my recommended 66 MPH "$weet $pot" Electronic Cruise Control Set-Speed.

If you have money to burn and do not mind breaking the law, go ahead and spend the extra $6.00 on gas to save an hour while chancing getting an expensive speeding ticket. On the other hand, if you want to save "Green" Petrol Bucks, conserve gasoline and would be happy getting to your destination at a mile-per-minute average travel speed, try ECC-Controlled cruising at my ---

66 MPH (2G/"cee") )/71 MPH (3G/"vee") "$weet $pot"

ECC Cruise Set-Speed.

On your next long "Open Road" trip, record your over-the-road highway speeds, trip fuel use and cost, distance traveled and "Chocks-To-Chocks" travel time actuals to see how your personal actual MPG vs. MPH results track against the results track against the Official EPA Miles Per Gallon Fuel Economy numbers.

SUMMARY:

"HYBRID $MART" DRIVING CONTRIBUTIONS TO AVERAGE MPG

Pseudo-Hypermiling/EcoDriving Pre-Operative Set-Ups:

"Up-Pressuring" Tire Air Pressure [Plus: 3+/- MPG Gain going from 35F/33R to 44F/42R PSI running on the OEM Low Rolling Resistance (LRR) tires for 2G/3G, and from 33F/32R to 51F/50R PSI running on the OEM LLR OEM tires for Prius v (vee) ].

Replacing Conventional “Dino” Oil with 100% Full-Synthetic Oil [Plus: 1.5+/- MPG Gain going from 5w30 “Dino” to 100% Full-Synthetic 5w30 for 2G].

Engine/Drive-Train Break-In [Plus: 2+/- MPG Gain after 10,000+ miles].

EBH and Grille Louver Blocking Insulation Foam (Very Cold Climate Ops Only) [Plus: 3 to 8+/- MPG Gain].

Use of Federal and State mandated 90:10 E10 "10% Ethanol Added" Gasohol [Minus: 1 to 3+/- MPG Loss]

Pseudo-Hypermiling/EcoDriving Operating-Driving Techniques:

Running HVAC From Fresh Air Vent Only Mode Through To Full-Time A/C AUTO Mode [Minus: 0 to 4-8+/- MPG Loss]
Employing Acceleration Technique of iMPG ≈ iMPH/2 When Accelerating From Dead Stop Then Seamlessly Transitioning To iMPG ≈ 1.1 To 1.2 Times iMPH As Travel/Cruise Target Speed Is Approached [Plus: 2+/- MPG Gain in Around-Town/Mixed City-Highway Driving].
Skillful Application of "Hybrid $mart" Freewheeling Coasting, Regenerative Coasting, and Regenerative Braking [Plus: 2+/- MPG Gain in Per-Full-Tank-Average MPG-FE for Around-Town/Mixed City-Highway Driving].
Consolidating Shopping Trips/≤ 2-Minute Errand Running [Plus: 0.5+/- MPG Gain in Per-Full-Tank-Average MPG-FE for Around-Town/Mixed City-Highway Driving].
Opportunistic Use of Advanced Fuel Conserving Warp-Stealth, Pulse & Glide, Dash & Coast and Super "Atkinson" Highway Mode [SAHM/SHM], Driving With Load (DWL) Techniques [Plus: 2+/- MPG Gain].
Driving at 66 MPH (2G & "cee") )/71 MPH (3G & "vee") Fuel Economy “Sweet Spot” ECC CRuise Set Speed, rather than 70-75± MPH for 2G, and 75-80± MPH for 3G and "vee," during Open-Road/Interstate travel that is 99.5% Freeway/Interstate [Plus: 3.5+/- MPG Gain For High-Speed Open-Road/Freeway/Interstate Driving].

TOTAL ADDED INCREMENTAL MPG CONTRIBUTIONS AVAILABLE FROM "HYBRID $MART" DRIVING

3 + 1.5 + 2 + (3 to 8) – (1 to 3) – (0 to 8) + 2 + 2 + 0.5+ 2 +3.5 = 8.5 to 21.5 MPG

PER-TANK-FULL FUEL ECONOMY FROM DRIVING "HYBRID $MART":

GEN II/2G: EPA 46 MPG [Combined] + (8.5 to 21.5 MPG) =

A "$MART" 54.5 to 67.5 Average MPG Possible

GEN III/3G: EPA 50 MPG [Combined] + (8.5 to 21.5 MPG) =

A "$MART" 58.5 to 71.5 Average MPG Possible

2012 C (cee): EPA 50 MPG [Combined] + (8.5 to 21.5 MPG) =

A "$MART" 58.5 to 71.5 Average MPG Possible

2012 v (vee): EPA 42 MPG [Combined] + (8.5 to 21.5 MPG) =

A "$MART" 50.5 to 63.5 Average MPG Possible