Ive got a 03 4x4 5.3 4l60e with 3.73s, would stepping up to 3.90s help with mileage any? If no mileage gain would be seen, would I be able to feel it pull harder? Im running a 305/50/20. Its the same height as stock, just a little wider.

 

I went from 3.42s to 3.90s felt a big difference!
Havent checked mileage but i dont see any big difference like a drastic loss.
i am 2wd and run a 275/45/20 tire 29.7 tall

 

My dodge axle only offers a 3.55 0r 3.90 ratio...no 3.73...

The 3.90 is a great all around gear, but still not worth the swap from 3.73....its like dropping 50lbs from your truck...does it help? Yes, but can you feel it? No! I would say its more a a performance swap..not much change in mileage

 

4.10s!!

 

4.10s are good, thats what i have, but i plan on switching them out, i need better pull and accel

 

I wonder what kind of mileage loss I would suffer if any by going to 4.10s. My truck seems to get best highway mpg at 73-78mph. I run around on the 55 roads @ 62 and get an avg of 18-20 mpg. Also for a carrier, whats a good street friendly posi unit? My G80 always kicks a tire out once you get the rear kicked out enough

 

What gears do you run now?

 

3.73s..

 

That size tire may be similar height to stock, but that set-up with 20's is going to be significantly heavier, adding rotating mass.
I'd run 4.10's at MINIMUM, if not 4.30's, which is what I run with 305/55/20 right now (thinking of going to 35's...), and sometimes wish I had just gone with 4.56. If the front weren't such a bastard to change I'd swap them out again.

How much expressway driving do you do?
I still take my truck on long distance road trips quite often and like to cruise right around 78-80, although pushing this box through the air will never result in good mpg at that speed, haha.

 

Geez.. I thought I'd be doing the truck a favor going with a bigger rim. Approximantely how much more do the 20s weight over stock????
The truck does see freeway driving once a month, some months it's many more times than others.
How do you like the way your truck feels with 4.30s? What's your mod list??