comparison

Comparisons
I became curious as to how the AY body Fifth Avenue stacked up against the older 1983-1989 M body version and the even older 79-81 R Body version.

Here's the tale of the tape:

Dimension	1990-1993 AY Body	*1983-1989 M Body~**	1979-1981 R Body~**
Overall Length	198.6 in	206.7 in	221.5 in
Wheelbase	109.6	112.6	118.5
Overall Height	55.1	55.1	54.5
Track-Front	57.6	60	61.9
Track-Rear	57.6	58.5	62.0
Overall Width	68.9	72.4	77.6
Turning Diameter	41.5	40.7	42.4
Head Room Front/rear	38.3/37.8	39.2/37.5	38.6/37.4
Leg room Front/rear	42/43.7	42.5/36.6	42.3/38.2
Hip Room Front/rear	51.2/51.9	56.8/56.6	57.6/58.2
Shoulder room Front/rear	56.4/55.6	55.2/55.2	60.2/60.1
Trunk cargo volume	16.5 cu ft	15.6	21.3
Fuel capacity	16 gallons	18 gallons	n/a
Standard engine hp/torque	3.3l V6 147/183	5.2l V8 140/265 165/240 CA	3.7l /6 85/165
Optional Engnie hp/torque	3.8l v6 150/203	3.7l /6 std some years (90/160)	5.2l V8 130/230 - 165/240 CA
Curb Weight	3425 lb	3770 lb	3911 lb

~Some stats will vary year to year
*Majority of M body stats from Allpar.com

**R body stats courtesy Drew

I must say, the results were a little surprising in some areas; it's often close but the old M body is definitely the larger vehicle, mostly evident in the width department. What's interesting is that despite a large advantage in hip room, the M loses out to the AY in shoulder room. Front head room also goes to the M, but rear head room belongs to the AY, though it's very tight. Not so tight is rear seat room, with an expected large victory for the AY. Height is interestingly spot on.
So what does this mean? Well, given the advantages in height, length, and wheelbase the M certainly is physically more massive. But except for hip room, the differences don't show up inside, where the AY at the least is really close, and in fact has better numbers in four of the eight interior measurements above, not to mention an advantage in trunk space to boot (pardon the pun).
How about in the power area? Well, each of the two AY V6's best the venerable 318 in horsepower, but the V8 bests all comers in torque. However, the M body is carting around 345 extra pounds. It also has the Torqueflte 3 speed tranny, a more efficent unit than the A604 4 speed, or even the *current* Chrysler four speed trans unit for that matter. So as a bench race, I'd have to give the old V8 a nod over the 3.3V6, but the 3.8 might give it a run for the money.
Drew wrote me to say that he felt even the 3.3 would be speedier than the 5.2 V8 due to the leisurely gearing of the transmission.
Now on to the monster R body. Despite it's quite significant size advantage, the EEK version still trumps the old R in a couple areas: Rear leg room and rear head room. It's also close in front room, except for width dimensions of course.
The old R was built in a time of fuel crises, and so the fact that power numbers are far from scintillating is not surprising.