I currently have a 2010 F-150 XLT 4x4 5.4L V8 stock and I want to put a 6in lift on it. It gets about 14-15 mpg street and I just want to know what kind of change I should expect in the gas mileage and if a shorter lift would make a difference. Thanks.

 

10 - 11 maybe............ depends on how big and what kind of tires you put on it.

 

I'm looking at 20in rims on 275/55R20XL's

 

Plus you need to regear on top of that. Otherwise you will loose low end torque.

 

You are going to run a 32" tire with a six in lift ? Why even lift it ?

 

14-15 street...consider yourself lucky and leave it alone...coming from a guy with an 05 that never gets better than 12 street...FWIW

 

You don't need a lift. That tire and wheel size were an option for your truck when it was new. I have the 275/55/20s on my 2014 SCrew, it came from the factory with them. Yes, lifting the truck will decrease fuel mileage as there is far more wind resistance. The higher the worse the fuel mileage. With a 6" lift I would expect to see a 2-4 hiway mpg drop.

 

Aint that the truth ! My 05 could roll off a cliff with the engine shut off and still only get 12 mpg's.

 

Ive got the same, 2010 f150 supercrew with the 5.4L, 6.5ft bed, 6in bds lift, 18in rims with 35x12.50 m/t's, it's also an fx4 with 3.73 gears. I've had it 7yrs since brand new with the same setup and get around 11.5 mpg city. I just got back from a 2k road trip from va to mi and back, and was running 65 to 75mph towing a light jet ski and was getting a tad over 13mpg (this includes mountain terrain). For what it's worth I do have a backflip, although I doubt it helps. I also have a light bar with lights out front that probably screws aerodynamics. Ive only put 32k miles on it in the 7 years so I'm ok with it. Another note, I do not think my Speedo was corrected for tire size, so I may actually be making slightly better mpg given I actually travel slightly further than the odometer reading, if I'm reading into it right.

 

My truck is only leveled 1-1/2 inches in the front using Bilstein shocks. By using P rated 33" lightweight Toyo's I'm still able to get close to 20 mpg hwy and 16-17 mpg in town. Not too bad for a heavy truck in my opinion!
Can't really tell much difference from stock height as far as mileage goes.