[CplLanders]

I bought an '06 Unlimited Rubicon a few weeks ago, and have since put a few hundred miles on it. I know what you're going to say...buy a Honda...but I'm getting right around 11 miles per gallon with the stock 31's and 4.10's. I got 15 or better with my '02 Sahara with 33's and 3.73 gears...and yes, I did change the speedo gear. Anyone have any ideas on why gas mileage would be so poor? Is it a new vehicle/break-in period thing? Any help anyone can offer would be great.

Thanks,
Mike

[BChamberlin]

Is it running well though? I was wondering if perhaps the computer is somehow messed up.

[CplLanders]

Shifting is a little difficult (clicks and takes a little effort to get it in gear), but other than that it runs smoothly.

[35sUnlimited]

Originally Posted by CplLanders

Shifting is a little difficult (clicks and takes a little effort to get it in gear), but other than that it runs smoothly.

Wow sounds like yours is a real mess. I'll do ya favor and trade ya my 04 unlimited even, and I'll deal with the bad gas problem. I wish they made the unlimited rubicon when I got mine.


Seriously, my gas milage was about the same till around 10,000 miles and then it climbed steady to around 15 mpg now. And that's with 33's.

[BChamberlin]

I imagine that's just cause it's new. Don't know what to tell you. There is a way of resetting the computer on older models. Maybe someone has the procedure here or you could do a search. If it's really bothering you, I'd get it to the dealer and have them check it out. Maybe something is set wrong. You sure you're calculations are correct? What size tank?

[CplLanders]

Miles driven devided by number of gallons used since last fill up. 19 gallon tank. I'm pretty sure my calculations are correct.

[TJgreg]

anytime you have a new vehicle, there is a break in period....about 1500k give or take. Until then, mileage will be a little worse. Just dont be surprised when youre getting 16 or 17 MAX

[CplLanders]

Thank you for your replies. 16 or 17 doesn't bother me...11 is just no good though. Thanks again!

[Erik T.]

14 mpg (HWY!)on my 01 Sahara stock with a cold/air intake.

Which is funny, because I found the originally dealer tag that was in the window telling the features and it says 15-17.

[autoX]

I had the same issue as you when I got my 05 unlimited. I was getting 11-13 mpg. As I understand it, there is a break in program on the engine computer. This takes around 6-8k in mileage to switch over. I just turned 8k and my mileage has increased to 15-17 mpg.

During the period of lower gas mileage I also noticed (when I checked my plug gaps) that they where off. They didn't really increase my mileage but helped the little hesitation around 1800 RPM.

Another thing to consider is with colder temps and winter blend gas will lower efficiency a bit.

Hope this helps,

[CplLanders]

Pete, that does help. It just sucks that I'm going to be burning all that extra gas for 3/4 of a year. I have also noticed that hesitation. Anyone know if they gap it differently for a reason, or if it is just an oversight? Thanks again.

[autoX]

Originally Posted by CplLanders

Pete, that does help. It just sucks that I'm going to be burning all that extra gas for 3/4 of a year. I have also noticed that hesitation. Anyone know if they gap it differently for a reason, or if it is just an oversight? Thanks again.

My guess was some worker with ham fists banged the plugs into the block before screwing them in. My gap was way smaller than they should have been. Helped quite a bit with the hesitation. I once in an while get it but like I used to.

[Ragtop_Rob]

I now have 10,000 miles in mine - I get 13 - 14 with the Auto

[UnlimitedFun]

When I got my 06 Unlimited I had pretty decent beginning mileage, about 14-15 mpg average. Once I hit around 9k, it went up to around 15-18 mpg. After 12k, I noticed it bump up a touch more to about 19 mpg average.

[CplLanders]

Thank you for all your replies, I guess I just need to wait out this break-in period.