tire size?

[strokedoutlaw]

got a couple questions, when im rolling down the interstate the trucks running bout 2100 rpms i have the stock 265/75s and am wondering if im correct that a 325/60s would drop the rpms a smidge second question is for them to fit i was thinking of putting the 350 rear blocks with a leveling kit and a rim with another smidge of offset and they should work, help me out if im wrong here please and if it would be a good idea for a little mpg bump up

[colo_dually]

With the wider tire any gain you would make with a taller tire, is counter productive with the additional drag created by the additional rolling mass.

What gearing are you running, what mods do you have, and what are your driving habits?

[strokedoutlaw]

im running matts srl+ with the atlas 40 and a 4in mbrp straight pipe, well i just tuned this thing last month so i still kinda get in it but not always, i drive shoot i dont know like i want the truck to last me a while but not like a grandpa, im not looking to go super huge on tires and lift i already did that with my old truck i want this truck to have a leveling kit at the biggest, i guess what im trying to get to is dropping the rpms which would gain mpgs if im correct. oh yeah its got the 3.73 gears

[colo_dually]

You might gain a little but not much. The tunes and how you drive affect the mileage more.

I strive to keep my RPM's under 2200, and boost under 10psi when I'm driving normally. This with a stock height dually with 4.30's, and I manage 13.5 mpg in town with tunes (12.5mpg under stock programming). Twice a week I go out and get at least one good WOT acceleration to keep the EGR valve and turbo healthy.

With a leveling kit and those tires I think you'd look right, just make sure you have the speedo calibrated for the new size when you're done.

[strokedoutlaw]

ah shoot forgot i had the egr deleted, i get after it every now and then to break the turbo loose for sure but im not that way all the time, every other week i go on a 300+ mile trip and this last time i got 17 but were i go theres a ton of steep hills that suck! i just got my ficm back from being repaired by ed so i could get better mpgs havent made the trip yet or checked my in town, i tell ya what though the atlas 40 improved driveability a ton