Gas mileage is a topic that people bring up a-lot. Our Jk's are Like people no two are the same. If I eat 10 Big Mac's everyday for a week and only gain 3 Lbs that does not mean my other Jeeper buddy is going to gain 3Lbs as well doing the same thing. There are just too many variables in a machine like a JK. i.e.. total weight, tire size, gear ratio, exhaust, programming.... I could go all day......... So lets put what we get and add your mods and highlight the one that kills MPG the most

Bumper and winch are adding some weight probably not enough to loose any MPG

 

2012 JKU
3" Level Kit
373 Gears
305/75 x 17's
Before 19 MPG / After 16 MPG

 

I have to say weight of the Jeep.toyo mt 285/75/17 and 3.5 lift kit 373 auto.wench and front bumper.

 

2007 JKU Auto w/4.10s
115,000 miles
11.3mpg

80,000 miles ago, when the stock tires were nearing the end, I was getting 21mpg. This was 100 miles a day all highway.

I added a 2.5" BB and drove for a few thousand more miles. I was getting 20mpg. (-1mpg = lift)

I added a 98lbs. wheel/tire combo (34x12.0R17) and dropped to 17mpg after recalibrating the speedo. (-3mpg = tires)

Now, I no longer see the highway, added a few hundred pounds in bumpers, installed a Gobi rack, drive nothing but stop and go traffic, let the jeep warm up for 10 minutes for the kids, oh and have lots of miles to equal 11.3mpg.

 

^^^^^^^^^^^^^^^^^^^^^^ Going from 255's to 305's really killed it 3 MPG?

 

Anymore takers? Looks like 15-16 MPG is the norm so far.

 

Now I average about 16.2 MPG overall. I drive 35% city and 65% hiway at 65 MPH. Mods are listed in my sig.

Before that when I was running no lift, 33s and 3:21s I could squeeze about 18-19 MPG if I really went easy on it.

Also in summer when I go no-doors and put the bikini top on, I notice it costs me about 1.5 MPG. I guess full doors and soft top has less aerodynamic drag.

 

07 JKU

Stock
4.10
285/70-17
15.5 city/ 17 hwy

Mods
3.5 RE lift
37 trail grapplers
5.13 yukons
AEV Procal
12.6 city/ 14.5 hwy

About a 3mpg loss.

 

I get about 16.5 to 17 in the city if I'm careful and can squeeze about 19 on the highway around 70. Depends on the headwind though.

Specs Below.

 

My 2013 auto with 2.5 lift, factory max tow 3.70 gears, and 15 inch rims with 12.5 by 33 K2 tires.
17.1 before mods.
16.4 after, tooling around Houston.
I chose the 15 inch rims and tires because of weight and rotating mass.