Originally Posted by Dave
Weight actually has more to do with it then people think. Vette is light, around 3200lbs so it takes less engine power to get the thing moving. They can afford to put tall gears into the car. An automatic Vette gets around 24mpg. All of this for about 1 sec less 0-60 time. Not bad! If you put 3.23 gears in the SS, it'll be a lot slower thanks to getting 1500 more pounds moving.
In order to get decent peformance out of the SS, they had to go to 4.11 gears. The SS was built for performance first, cruising second.
Aerodynamics takes its toll also. In the USAF we use to call the F-4 a flying brick. One fast brick but it was not aerodynamic and it sucked gas. The F-16 is very aerodynamic and can fly just as fast with only one engine (and about 2/3rds of the weight.
Now if you look at a 0-60 time of 5.5 sec or so for a 4500 pound SUV that can carry 5 in any weather conditions, then the gas mileage isn't that bad.
Yea, the 4.10
s make a huge difference in mileage, I know in my 02 TB I6 (with 3.73s) I can get 21.5mpg crusiing at 75 for 350+mi on one tank and the RPMs are like 2350-2400. Going to 80 they rest at 2500-2600.
Im glad I didnt get the 4.10s, as my mileage would really suck. Right now, Im only getting 12mpg because I rev to like 4000-4500rpms every time I can, so going to an SS wouldnt be all that bad except on the hwy mileage.