Usually when a engine is new and breaking in it tends to use a little more gas, have you guys noticed this in your JK's or not?

BTW I now have a little over 200 miles on it and it is averaging aroung 15.8 mpg which is fine but I'm just curious.

 

I'd say your about right, takes a few thousand miles for the jk computer to learn your driving habits. You should go up a couple MPG's after or by your first oil change. Mine did anyway, then I put 35's on

 

I had the same experience as mkjeep. Everything changed all at once I just don't remember when it was.

 

x2

My MPG improved after 2k miles and an oil change.

Then is dropped after the 35's

 

Agree with others, you should see improvement over time.

 

I track my MPG faithfully, and saw a modest increase around 2K-3K miles.

 

5k is the break in point. mileage keeps going up around 3k and lrvels at 5k

 

I also track every gallon of fuel that goes into my Jeep. By looking at actual lifetime MPG (odometer / total gallons), I went from 13.5 MPG new up to 16 MPG at 2300 miles (pretty much linearly), and then a pretty steady 16 MPG ever since.

 

13.5 mpg dang, sounds like im doing good for break in with 15.8.

 

Yeah, I noticed that when my Rubicon was stock. It went up until the computer learned my driving style -- at least that is what it appears. I don't think my mileage was ever that low though when I was stock. Heck, I'm getting that on average with 35s running 5.13s.