i'm running 315/75/16 on a 2wd 5.3

had 3.42, truck was a TURD, got a best of like 15mpg.

Got a new rear with 10k miles...3.73 g80 locker. Truck is a little better. If it's raining, i have to feather it, and can kick back end out up to 35mph if i hammer down. If it's dry, i can normally get a small squeal/chirp....but truck falls on it's face until about 15-20mph, and pulls strong til it shifts at 45ish....then back on it's face until 65ish.

At 80-90 mph, i'm turning about 2000-2200 rpms. Bogs out real bad...downshifts at most hills...get like 10-12 mpg

At 65, barely have to push the pedal. Get about 14mpg, doesn't downshift unless the hill is steep.

Truck gets GREAT mileage at 45-50mph (well..great for this gas hog...get like 17-19 at this speed)

I plan on putting in a 4.56 when funds permit. Should bring my optimal speed for gas mileage closer to 55-60. Will be turning a lot more rpms but will be less of a load.

At 65mph, i actually get better gas mileage in D then OD.



i just ordered some software to monitor how much fuel I'm using, to calculate instantaneous mpg. I will make a log of this over a road trip, and post results.


**sorry about the novel**