Should I change gear ratio?

[srziemkowski]

Your Gas Mileage Will Ghange As Much As You Truck Will Though

[hog]

Your Gas Mileage Will Ghange As Much As You Truck Will Though

He is probably lugging the engine quite a bit with 3.08's. A 3.73 will probably help his city fuel economy, and if he doesnt cruise too fast, his highway economy might increase as well, esp. if he lives in a place with a lot of hills.

Youw ant to cruise with teh highest engine vacuum possible. More TPS means less engine vacuum which means less mpg.

my Vortec 350 with 3.08s would lick out of TCC lockup and downshift into 3rd on large hills with teh crusie control engaged. With my 4.10's the TCC would stay locked and teh trans would stay in 4th. 4.10's and 28" tires were too much fopr 70+mph crusing withmy 4l60e's 0.70:1 OD ratio. The 3.06:1 1st gear and 12.4:1 final drive ratio made for some excellent 1st gear acceleration however.

peace
Hog