Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

Gas mileage change from leveling

Recommended Posts

I have a 2008 GMC Sierra 1500 crew cab with a 5.3, AFM has been disabled 


Right now I have a 3.5 in lift plus Bilstien 5100 so I’m at about 4.5 total lift with Tokyo mt 33x12.5, my mpg is about 12-15 highway and awful in the city. I’m think about going back to just a leveling kit and decreasing the tire size but I want to know if I’ll see any noticeable gain in mpg. I’ll also be getting a k&n intake and hopefully some long tubes so that may help some. Anyone have any idea what kind of mileage I can expect (I do have a heavy foot in the city but cruise control is always set on the highway 70-75 mph)


Thanks in advance 


Link to comment
Share on other sites

If you don't know what programming the truck is running, nobody can really tell you what doing headers and an intake are going to do, but it's unlikely either will result in you getting better MPG.


I would suggest getting your truck flashed back to stock, then perhaps buy a tune to match the upgrades you've done/will do, and how much performance you want.

Link to comment
Share on other sites

Just getting rid of the heavy mud tires would help a lot. Maybe 1-2mpg easy. Then going back down a few inches would get back another 1-2 mpg. A truck like that going 65-70mph should have got around 20mpg when it was stock on the freeway.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

By using this site, you agree to our Terms of Use.