99TJ,been a while

I'm gonna recommend getting rid of those big tires and the lift. We just had a mileage thread here but it didn't get very far.

Earle

I just had a 4.5" lift installed (still running same small tires (235's?)) and haven't noticed a drop in MPG (still bad at 13-15 city).

I AM WONDERING though about the effects of a safari rack, once I get one :/

...

I think that the two things that made my lileage drop from 14-15 to 10-11 are the 33's and the light bar on top. I can't imagine the lift made any difference at all.

Kate

I just had a 4.5" lift installed (still running same small tires (235's?)) and haven't noticed a drop in MPG (still bad at 13-15 city).

I AM WONDERING though about the effects of a safari rack, once I get one :/

...

Any lift increases your aerodynamic profile and therefore the amount of work necessary to get you down the road. In a shoebox on wheels aerodynamic drag is the big factor. The best thing you can do is to get low down to the ground and keep your speed under sixty. That said, in a Jeep fuel economy isn't everything. Getting over stumps and rocks has to be worth something.

Did you change your speedo gear to compensate for the big tires? Maybe you only think you're getting 10-11 mpg. Your shift points could now be wrong too. I am not sure, but on the newer ones maybe all you have to do is get the dealership to reprogram the computer. It won't hurt to call them.

Earle

Well, getting rid of the tires isn't going to happen just yet as they're brand new and maybe later I might go get some decent "pull off" tires. (should've kept the oem tires I had them pull off when first set of bfg's and I got my lift. ha. but then, I should've kept my yamaha 650 special too.)

I was just th> > hiya,

Maximum recommended tire pressure, and proper rim size for the tires, will prevent your tires from being a source of decreased fuel mileage. The same with replacing the spark plugs, air cleaner, etc. before they go bad. But as you know, optimal off road configuration and optimal on road configuration are different.

Earle

I have a 4.5" RE lift on my rubicon with 33x12.5 geared at stock

Take care,

Hey Earle, Yes I did have them reprogram to the 33's but the other day the speed sign on the edge of town was telling me one thing, and my speedometer was telling me something else. I think it was saying I was going about two miles faster than the Jeep told me I was... I don't remember for sure, I was busy driving, not watching all that stuff. Maybe I should have it rechecked.

K.

Did you change your speedo gear to compensate for the big tires? Maybe you only think you're getting 10-11 mpg. Your shift points could now be wrong too. I am not sure, but on the newer ones maybe all you have to do is get the dealership to reprogram the computer. It won't hurt to call them.

Earle

Interesting you say that Kate, on my new (to me) 07 Rubicon with stock tires the speedo indicates 2 mph faster than the speed on my GPS indicates. Consistent at all speeds. I haven't come across one of the speed signs yet to compare there. Nice thing is that I'm getting about 16 mpg...according to the trip computer...which is probably flawed because of the speed discrepancies...

Jerry S.

The suggestion to have it checked with a GPS is a good one.

Cheers,

Earle

The one I have for geocaching doesn't do that, but the hubster has one that does... I'll check it out and post the results.

K.

Cheers,

Earle