So I've been keeping track of my gas mileage and I'm getting from 9.4-10mpg in the city and 11.0-11.5mpg on the highway. Its an 03' 2500 LD 6.0 4x4 with 155k miles. I do have 33"x12.50"x16" A/T tires and a 2"leveling kit. But is this kind of mileage normal for what I have? The truck is stock except for a S&B cold air intake. Plugs and wires have about 8k miles on them, seafoamed about 6k miles ago. Any ideas on improving this a little bit? I'd love to see 11mpg in the city! lol

 

i got about the same in mine when i had it and 13 on the hiway till i put a turbo on it...it got better.

 

That's some icky mileage. I had a '03 2500HD w/ 6.0L, lifted 9" and on 35's and I still got around 10-11MPG average... What kind of fuel are you running, and are you getting any codes?

There's usually quite a bit to be gained with a proper exhaust setup, and you can usually pick up an MPG or so with a quality tune.... Sort of all depends how much money you're wanting to put into it.

 

that's about what I get with mine . . . it'll get 18-19 when going 65 . . but thats too slow for the freeway

 

Do you have a 6.0 or a 8.1? Are your tire pressures where they should be? air filters?

 

Stock exhaust, 6.0, stock tune. Just a cold air intake with lifetime filter. I usually keep the tire pressures up around 40psi. I mean I have a 10 second, 95 Z28 that gets better mileage than this thing, haha.

 

I should have read more closley. Are you carrying aftermarket bumpers made of iron? haha.
I dont know your max pressure your tire can hold but 40 seems low. I run 20s and have them at 50 psi all around. what does the sticker on the inside of the drivers door recommend you set your pressures at?

 

Another question is what gears do you have 3.73's or 4.10's? Also is it an extended or reg cab?

 

Check your tire pressure, check your air filter, and clean your MAF. Should help a little but I am afraid you will have to live with the MPG as your set-up is not known for being fuel friendly.

 

Save your money for more gas. You will never recoup the money spent on the mods it takes to make slightly better mileage unless you drive a assload of miles over the life of the vehicle.