Regearing just for mpg and no plans for bigger tires is a waste of cash. You are very close to what the truck is supposed to get for mpg.

Estimated EPA Fuel Economy for the 5.9 is (MPG City/Hwy) 1500 2WD: 13/17; 1500 4WD: 12/16 auto.

For the 5,2 it's Estimated EPA Fuel Economy (MPG City/Hwy) 1500 2WD: 13/18 man, 13/19 auto.; 1500 4WD: 13/17 man., 12/16 auto.

 

Wouldn't you actually lose mpg re-gearing and not going to a larger tire? I would regear if you want your truck to go faster from bigger tires but not for trying to save mpg.

 

It actually IS possible to get better fuel economy from lower (numerically higher) gears. IF (and only if) the new gears put the engine more into its peak power band. Otherwise, you just get better acceleration, lower top end, and worse fuel economy.

 

What is the powerband HeyYou? I think it heard its between 2000-2200?

 

Mines right around 2000-2500 before it starts to drop off.

 

I've got 4.56 and at normal speeds I'm at 2100ish with 35s. I used to have 3.55 and drove with 33s for while. Hated it. Took a long time to get up to speeds. Then I changed to 35s and wow.. It would downshift on a straight stretch!!! I went with 4.56 and will never look back. I gained probably 1-2mpg all around. It town it is a lot easier to take off and at highway speeds it revs higher but it's not downshifting anymore.

 

4.56 and 35's puts you right in the neighborhood of stock RPM/Speed.

Our trucks seem to start out right around 16-1700 RPM, and it pretty good up to around 4K or so. (but, you don't wanna cruise at 4K) I am thinkin' if you keep your RPM right around 2000 at your typical cruising speed, that would probably be right where ya wanna be.

At 55, I am right around 1500 RPM in O/D, and that is just too low so far as I am concerned.... I am looking at doing 4.56, and 33" tires.... which will bump RPM about 200 or so at my typical cruising speeds. I don't do a lot of freeway driving, so, that aspect doesn't really bother me. (currently, at 70 MPH, I am right about 2200 RPM. I think.)

I have 265/75/16s and 3.55s at the moment.

 

What would be the round-a-bout price to switch gearing from 3.55 to 4.56? I have 33" tires on mine and like everyone else, i have to down shift like crazy to just go up hills and pass people when at speed. I'm not so much doing it for mpg as i am for just less stress on the tranny.

 

Including labor and all the parts $1200+ est

 

Depends if you buy thick gears or a new carrier for the front. The stock carrier won't work with that low of a gear. I would assume 800-1000 for parts + installation. So probably 1500ish. My install was a little more pricy as I added lockers but I did it myself.