i have that exact combo of lift and tires, i have managed to get 20 MPG on the freeway with a custom tuned SCT econo setting. not too sure on the city mileage..

 

wow 20 really the best I have ever got with this combo is 15 now this is without a tuner and 373 gears. I really average about 13-14 combo highway city driving.

 

I get 15 with custom tunes and 4.10 gears

 

Is 17mpg a realistic possibility on the interstate? If I can do that I'm going to try and buy this truck.

I could also drop down to 35's once the 37's wear out...

 

I may have missed it, but what gear ratio is in the truck? I'm running 8" of lift with 37's and 4.30 gears. After a 4 hour round trip I checked my mpg, and I was just under 14. And I kept it below 75.

IMO, the only way you're going to see 17 mpg on the highway is to keep it at 65 mph or slower. Tough for me to do when the speed limit is 70 and everyone goes 80.

Now that I think back, I never saw 17 mpg bone stock on the highway. I had a few 15-16 mpg tanks, but never 17.

--Snake

 

With proper tuning yes its realistic

 

Right after my lift and tires I was only getting 11. After a regear to 410's, I'm getting 13. This is highway and unloaded.

 

with my banks tuner I was averaging 17 or 18 mpg's, now with my custom tuned sct I'm pushing about 15 or 14 highway.

 

realistic if you dont go 75...thats the only way.

Tried innovatives econo, it makes the truck run horribly, spartan shifts weirdly and DJ's seems to work well, but not 17mpg on the hwy. maybe just over 16

 

i get -13 mpg's on 40's....so how are you guys getting the same on 35's and 37's? I figured that 18 or so was reasonable for smaller tires....I have a Superchips Cortex programmer, Rolling Big Power TB exhaust and an AirAid Intake

 

17.5 here, 6.5 procomp with 35's.

 

I have the same size lift and tires. Stock tunes I average 15mpg.
Economy tunes 17mpg.
I am usually hard on the go-pedal

 

are ya'll hand calculating your milage or is it what the display on the truck is reading?

 

You need to do it by hand a few time and check the display. Once you know it's accurate.... I only use the dash.

 

hand calc. display would be quite wrong unless it was calibrated..off by about 15%

 

I don't know what the gearing on the truck is. It does have an aftermarket rear diff cover so it may have been regeared for the lift and tires.