Hey, I have a TJ with 33's and a 5 inch lift kit. I am considering the JK and would immediately replace the tires with 36's or 37's. I'm just trying to do a little comparing between my MPG and yours, PLEASE POST YOUR GEAR RATIO, TIRE SIZE, AND AUTO OR MANUAL. I seem to be getting around 12 MPG. Feedback would be appreciated, thanks guys.

 

2DR or 4DR?

 

Everything will be considered, I would just appreciate if the owner posted all specs and everything so I know how he is getting the MPG posted. Thanks

 

Or she?

I'm interested to see what people post too because I just had my lift, gears and tires installed Friday and had it on trails all weekend, and I could swear that my gas mileage actually improved (significantly). But I need to track it this week to get some hard numbers. I do know that it is much higher than the 12 mpg you're getting now.

Mine's an automatic 2DR with the 3" FT Ultimate, 35" tires and 5.13 gears. I had 4.10 gears originally.

 

On the highway I am getting about 20 mpg at 70 mph and about 15 mpg in the city with about 10 - 12 mpg off road. The mpg is checked by hand but the computer is a bit off from the tire size. My jeep is a auto. My mpg went up when I added the snorkel too. 6723 miles now.

 

Maybe this is a "stupid girl" question, but isn't the weight of aftermarket bumpers, winch, etc. going to affect mpg also?

 

Yes... But probably not too much... the main challenge the Jeep has is it's lacking in the areodynamic realm. It's a big brick trying to cut through the wind, so I don't think you'll see much difference w/various tires sizes... from what I've seen, you'll probably loose 2-3 mpg from stock when going to larger tires as long as you regear.

I get around 15mpg city and around 18 highway. This is hand calculated and is +/- 1 in almost every fillup I've had so far.

35's
Auto
5.13's
4dr

 

Unlimited X with Auto and 4.10. Added a TF 2.5 BB and Maxxis 305/70-17 tires (34"). City did not change much, but highway dropped. And yes, I adjusted the post-lift MPG for the increased tire size. OEM tires were the crappy 255/75-17 Goodyear SR-A at 32". Didn't want to go to 35" and have to regear. Highway power is bad enough with the 34"'s!

Pre-Lift (11,500 miles)
Min: 14.5 MPG (City)
Max: 19.7 MPG (HWY)
Avg: 16.6 MPG
Trip Error: 5.6%

Post-Lift (2700 miles)
Min: 14.2 MPG (City)
Max: 16.0 MPG (HWY)
Avg: 15.1 MPG
Trip Error: -4.5% (Not adjusted for the lift)

Seems strange to me that the mileage dropped that much. The final ratio to the pavement with 34"/4.10 is very close to the 32"/3.73 that '08 have now. And the reason for the gear change for the '08 was to increase gas mileage? So reduction in MPG must be a function of increased tire/rim weight and tire width.

 

I'd be curious to know what people are getting with just a 2" BB and 285 tires (no bigger than 33"). That's basically the setup I will eventually be running.

 

X2