my best friend has a 2005 chevrolet 2500 hd with the 6.o litre and he aint likein the gas mileage especialy on the highway now he dont tow anything so a loss of towin power aint a big deal and we were curious if anybody knew a gear for the axles that would bring down the rpms on the highway he likes to do around 70 75 i dont know jack bout gears lol so any help would be awesome and i appreciate any advice thanks guys

 

I should say do a search in the 8-lug section, but here's the thread anyway.

https://www.performancetrucks.net/fo...d.php?t=441502

 

thanks man i appreciate it

 

Tell him to have it tuned for gas mileage...

 

wat do u guys think about 3.42 and its a automatic i belive its 4 speed but im not sure and gettin it tuned would work if we could find someone around here to do it lol supped up cars and trucks aint to big around here unless u condsider a civic with rims and a wing supped up lol

 

3.42s and a 4l80e, there is a reason they didn't come from the factory that way...

the lowest I would drop would be 3.73s, but if the truck is 4wd, it would be no where near worth it to swap gears to save money,

You can also put a larger tire on to drop the rpms,

I was getting 14 to 14.5 mpg in my 2500hd 6l 4.10s with 33" tires an intake, muffler, UDP, and a tune. But I have a 5spd.

 

i wouldnt change the gear ratio to a 3.42, the lowest i would go is to a 3.73. but i agree with blownhd if its a 4x4 its gonna cost around 1700$ to switch the front and rear out, a cost that will take a long time to recoop in savings of gas mileage.

btw people buy 2500hd trucks to pull things with, it might make it hard to sell with a 3.42 when people are looking for a tow vehicle.

 

I dont see a problem with him running 3.42s? yeah it'll be a slug but the guy wants highway gas mileage. Yeah its gonna take away most interest when he tries to sell it but he can always swap em back if he does try and sell it.

 

You could try a Gear Vendors or US gear over drive unit. That way you can get the best of both worlds if there is any gain to be had.

If you have the 4.11 gears I'd try the 20% unit to keep the rpm around 2000