MPG after Mods?

Whiskey Bent · September 28, 2014

I was wondering what kind of fuel mileage I can expect after a RC 2.5" and running a little bit bigger a/t tire? Don't want anything crazy just lift it up a little and fill the wheel wells up a bit. I have a cc std bed and right now I'm getting 20-22 mpg.

jaysen · September 28, 2014

im wondering the same... From the research and threads I've been in, most say you can "expect" a 1-2mpg decrease, especially if you remove the bottom air dam.

Not sure if I am totally convinced on that estimate, but have no reason to doubt.

Whiskey Bent · September 28, 2014

I know for a fact on my 07 grand Cherokee I saw 1.5 a 2.5 mpg decrease with a 3" lift bigger tires and removing the air dam. I'd like to stay around the 18 - 20 mpg range if possible doing the level and tires. Not planning on removing the air dam as of right now.

Spurshot · September 28, 2014

I saw about 2-3 mpg loss from a 1 1/2" level and 33x12.50x18 LR E tires. I kept the air dam. I'll probably keep it until I rip it on some rocks.

Whiskey Bent · September 28, 2014

Wow! That's more than I was expecting. Wonder how much the 2.5" lift decreases?

Deerbio · September 29, 2014

I did the 2.5 RC level on front, kept the rear stock blocks and changed to toyo at2's in 275/70 on stock 18's on my z71 crew. Went from 18.5-20.5 factory to 17.5-19.5 after mods. Did not remove air dam. Lost a little, but like the looks of it. Well worth the slight decrease in mpg's. I also added a Bakflip G2, but doubt that increased mpg's.

310racing · September 29, 2014

2" level, haven't added tires yet.

Removed the air dam, but ended up trimming and adding it back. Took about 2" off the sides, looks much better, and still hides the mounting holes.

18.5-20.5 mpg, mostly short trips

Whiskey Bent · September 29, 2014

Well that's not too bad. I know it won't account for much but a tonneau cover may give some fuel mileage back after a lift and tires. At least I hope it does. Anyone with real world numbers as to mpg loss/gain for there mods in step by step after each mod?

blackout07 · September 29, 2014

The level and air dam removal won't cause much, if any decrease. The tires / wheels are the main culprit.

bladz1454 · September 29, 2014

The level and air dam removal won't cause much, if any decrease. The tires / wheels are the main culprit.

Exactly, if you do a level with no change in tires you won't see a difference in MPG (make sure you get your truck realigned obviously). I've heard mixed reviews about the air damn, everything from no change at all to -0.5 mpg but even if that is true, the only people going to see that are people that do like all hwy driving.

Big Whiskey · September 29, 2014

As stated, the leveling kit and air dam removal won't change much. You might lose 0.5-1.0 mpg, on a long highway trip, but otherwise, you won't notice much change. Bigger tires are what hurts. If you stay with a P-rated tire, and only go up a little in size (like to a 275/60/20 from the stock 275/55/20, or to a 265/70/18 from the stock 265/65/18), you won't notice much change at all. Maybe another 0.5-1.0 mpg on that too. If you go to a 10-ply (E-rated) tire, in the wider, 33"-34" range, expect a 2-4 mpg loss, depending on your driving habits and rear-end gear ratio.