danfsc04

I am in the process of researching the '08 JK's for my next vehicle and was wondering what the difference in mpg is from a stock jk with 3.21 gears to a stock jk with 3.73 gears

Bingville

I owned an 07 jk w/ manual trans. & 3.21 gears. I upgraded to an 08 auto, w/3.73 gears. I decided I liked the modular hard top & air. Long story short, I have noticed for whatever the reason the 07 w/ the manual & 3.21 got way better mileage. I have only 800 miles on the 08, but so far no where near as good as the 07. Maybe more break in will help. Good luck!!

08 JK, auto, hardtop,air, mopar slush mats & locking gas cap, premium spare tire cover.

BaltChief

If you go 3.21 make sure you go manual. An auto with 3.21's is a dog.

cars47

I just filled up my 08 2 door X...manual trans...3.21 gears....625 miles.... tonight.....254.3 miles...14.478 gal....17.56 MPG....

BaltChief

OUCH.....I get 17 to 22 depending on highway or city....well that was before my new tires, with 34's I'm getting 15 to 19

08red6spd

You should probably wait until you have more mileage on it. Once it is broken in you'll have improvement and a more accurate idea of the mileage

echofoxtrot

With a 2 door six speed with 3.21s I get in the low 20's (MPG) maxing out at 24 if I'm driving nicely on a long trip. I imagine with 3.73s *but still a manual* you would only suffer very slightly. An auto would make a few MPG difference, since it's gears are so far appart (4 vs. 6) and it can't anticipate changes in the road like you can.

Note that I have an X and it is pretty much completely stock w/ a hard top on, which is the more aerodynamic of the two tops. I am also a very smooth driver. If you plan on modding it, this all goes out the window.

pearl-drum-man

You can only get the 3.21's in the manual, 3.73's optional. 3.73's standard in all autos. All Rubi's get 4.10's.

Bingville

Pearl-drum-man is right. At least with the 3.73 you will zip right along. In New England I climb the highways around Vermont & N.H. and I climb the hills in the left lane no problem. I have yet had to pull over to the right because I was slowing down. Gas mileage is another story. Red 6 Speed is right, I probably need more break-in.

IndianaJK

08 with 3.73 automatic, I get 16 in town and 19-20 on the highway.