Andrew k

Hey guys, I'm curious as to what kind of mpg and performance difference there is between 35" tires and 37" tires. Is it a lot or barely noticeable? I will get the 4.10 gears and a six inch lift. What thoughts do you have on 20" wheels.

pullin hard

your question is lacking info we need to answer what you ask.
what gears do you have now?
what tires do you have now?
what mods have you done so far?
what are your plans for the truck in the future?
what do you use the truck for?

Andrew k

I presently have the 3.73 gears but am planning on installing 4.10s soon. The only towing I do is about 3000# six times a year. I am mainly running empty on the highway and a little city.

cquestad

35s w/ 3.73 and 37's w/ 4.10's are a good combo if you have a little extra power. Stock power...you will feel it.

Between the two combos above...depending on driving style and location...you may only loose a little. Your lift height will cost you more than the tires...

If you are a short box...I personally would keep your present gearing...run 35's (no opinion on whether you are a big wheel versus normal wheel type dude...I am a normal wheel dude) and get only a 4-5" lift. That will give you an awesome truck...very drivable and avoid many of the issues with larger lifts and even worse mileage.

Long box...build it like mine or a few others on the site that have 37's, the correct wheels, 4.10 gearing, anf only 4-5" lift. The longer the truck...the lower it looks.

JMHO

Andrew k

Thanks, thats some very good info.

pcburnout

My sig tells all I have and my truck gets up like a jack rabbit and if i'm good to her she gets 17-18 mpg at 55mph

BCarmicle

I would personally stick with the 3.73 gears. I am running the 20" wheels/35" combo and have 4.10s. I would personally like a little higher gear on the highway to yield better fuel mileage.

Also, if you ever plan to drag race and put your stock tires and wheels back on then you will be restricted by the rev limiter if you have the power to get there.

Brandon

Fummins

37"s here with 3.73,coupled to 48re.Dyno at 403/738 with my mods,

pullin hard

i too would stick with the 3:73 gearing, i have the 4:10's and 315's on my truck.i love the gearing, but on the highway, it revs out a little too much for me. i think that the revs would drop a bit more and be more normal for cruising on the highway, and i don't think i would notice it much around town. lots of bottom end to these things, so gearing not so important when you don't do alot of towing, which is my case .

jr183

I have a 2005 w/ the G56 and 37's. I am definately keeping the stock 3.73 gears. The acceleration is just fine and the highway rpm is much more reasonable. With the stock tires, I was at 2350 rpm at 70mph. Way too high for me and any kind of fuel mileage. The engine is stock for now and turns the 37's just fine. If I had the NV-5600, I still would recommend the 3.73's.

J.R.
Denver, CO

4x4not

I have the 4.10s now with stock tires and the RPMs are too **** high on the highway, but I was and still am planning on 315s or 35s....

Andrew k

How does it work on big steep grades with the 3.73 and the 37s? I mainly run empty.