I went and talked to a guy in my neighborhood about his JK because he has the exact wheel setup I plan on doing and I wanted to get his take on it. (285/70r17 duratracs on 17" pro comp 7005s)

My concern was the gas mileage as it will be my daily driver. He said he put a 2.5" lift up front but nothing in the back, obviously making the front end higher then the back. He said he gets around 13mpg city. does the higher front end cause the worse gas mileage?

I plan on doing the same wheels but with a teraflex leveling kit. should i expect my mpg to be just as bad as his?

 

Raising the front end, especially higher than the rear end, will create more aerodynamic drag.

 

so adding a leveling kit wont make me get as bad as mileage as him?

 

That one point will probably not be as bad as his. But, there are too many variables, including the differences in your driving styles, to know if you will get better mileage than he gets.

Do you know if he reprogrammed his Jeep for the bigger tires? If not, that will make his gas mileage look worse than it actually is.

 

I forgot to ask but vary possible that he never did reprogram. I'll have to ask the next time I run in to him

 

The actual rolling resistance difference between the two tires will also dictate a difference in the MPG. Boggers vs Wildpeaks will yield different results.

 

Do you know if duratracs are good tires for better mileage?

 

They'll be better than mud tires since they're "all terrains" and have a decently low rolling resistance.

 

With a 2.5" lift and 285/70/17 Duratracs, I sustain about 20.9mpg highway (2 door, 3.6, 3.73's, manual). That's down from 22.4 which is what I could eek out with my stock tires. It will start dipping into the mid 18mpg range with lots of traffic, stop/go.

Bigger tires/wheels are heavier, harder to get going, harder to stop, and generally have more rolling resistance than what they replace (smaller tires). Leveling the vehicle exposes the underside of the vehicle to more air currents and more wind resistance; lifting the vehicle and leveling it really expose the underside.

If you do a tire upgrade and have an automatic trans, definitely get a programmer to correct the shift points because of the new tire size. Helps with efficiency. It will also correct the speedo so your speed and mileage calculations can be spot-on.

 

Any additions to your Jeep will generally subtract mileage. I, too, am concerned with MPG's so I pay close attention to it.

Bigger tires, lifts etc will certainly reduce your mileage, but if you must do those things there are ways to maximize your mileage and they all include technique.

- keep your back window cracked open as much as possible so it doesn't act as a parachute.
- stay under 65mph. Mileage drops beyond that number.
- accelerate slowly. Mashing the pedal kills mileage and isn't good for your engine any way.

My 2008, which I bought new, is routinely at 19 or 20 when I drive like a Gma with nothing in tow and 12-14 if I am either towing or driving very fast for some reason.

I can get 30mpg put of a stick by hypermiling.