The 22 value occurred during a trip to see my Marine son at Parris Island. It was literally 100% highway. Filled up on highway, drove on highway until it was on E.

 

Lift & heavy weight of tires hurts. Also, did you leave your air dam in place, or remove it? My coworker has a 2012 rubi manual trans. He only gets an average of around 15.5mph though he is hard on the skinny pedal.

 

I have a '13 Rubicon with 4" (actual measurement) of lift, 6 speed manual, 4.10 gears, stock tires (on purpose for the commute, I have 35's for offroading) removed that silly airdam and I am getting 18-19 mpg mixed driving. Tires are killing your mpg's.

 

I just drove 1200mi to Virginia then back. 2014 stock Sahara, 3.73, soft top, loaded with gear and cargo rack got anywhere between 18.5-20.5 depending on what gas station. I don't trust the computer so I do mine by hand every fill up. Putting my rock hard bumper and 2.5lift next week and will see how it goes.

 

2012 JK sport, 33's with a 2.5" lift, stock 3.73 gearing, 6 speed manual hardtop, steel bumpers and a winch...

It consistently gets about 21-22mpg on highway trips depending on wind conditions.

When it was bone-stock, it would hit over 24mpg on the same trips.

With mods, now, in mixed driving, it will come down to 20mpg or so, but it really doesn't see much/any city driving, so it's hard to tell what it would get in a worst case scenario.

I don't keep track when I'm 4-wheeling. I just keep an eye on the tank level.

 

2014 Sahara Polar edition completely stock for now so just the stock 33s on it. With my 30 miles just to get to work I usually get 21 but have gotten 23 and half and love it haha

 

Summer highway MPG, hand calc with calibrated odometer.
MPH MPG
55 ~20
65 ~19
75 ~17

City, winter, and off-road MPG vary widely depending on the usual variables.

2008 JK Rubi, 4.10 gears.
33" tires [GY Adventure AT, 285-70/17]
2" OME lift.
View Profile: Mr.T - JK-Forum.com

Very happy with the tires -- good off-road and good on the highway. MPG is essentially the same, or slightly better than it was stock (BFG KM tires).

 

I PITTY THE FOO, THAT DOESNT RESPECT THESE MILEAGE NUMBERS.

 

That is pretty consistent with what I see. Slowing down to 65 MPH gives me about 2 MPG over 75 MPH. From somewhere around 12-14 to 14-16. My speedometer is calibrated, numbers are hand-calculated.

Just curious, who else has noticed that the Jeeps get a couple more MPG when burning mid-grade fuel at higher altitude (bear in mind that mid-grade at higher altitudes is 87 or higher)? I get a little improvement at regular (85-86 octane), but definitely see an improvement in performance and gas mileage at high altitude if I stick with the 87 and higher octane. I run with a lot of different folks, and many of them have remarked the same thing to me.

 

If your having any fun at all 21 is probably the number from my experience.