however even with 3.21 gearing, I bet if you take actual manual reading you will find its more like 17 mpg 19 these readings are not correct . I don't know why they even bother to put them in the vehicle , except to maybe fool the customer into thinking he gets good mileage , and will tell others to buy a jeep their not bad on gas

 

I can get 60 mpg driving down stretches of I70 heading back to Denver. How you like them apples? (Insert sarcasm)

 

yeah, you really have to take this stuff with a grain of salt. Personally, I don't care what the gas mileage is, I have wanted a jeep since I was a kid and would have gotten it even if it got 9 mpg like my 92 bronco did.

 

Not sure how you figure this. Every time I fill up and hand calculate my MPG, the computer readout is within a few tenths of being correct.

 

Same here, mine's been almost dead on as well (after programming for the correct tire size)

I find it amusing that I usually average 17-18MPG when driving from Chicago area back to Michigan, but when I'm coming home from Michigan its usually more like 14-15MPG.
It's that damn jet stream I tell ya!

 

There is probably more "against the wind" driving in the return trip... which is a killer when you have the aerodynamics of a brick.

 

I have gotten about 24 MPG on my 2011 Call of Duty, driving stick on I-95, but this is outstanding!

 

Interesting observations: (long trips and temp)
Just pulled multiple leg trip, monitoring tire pressure and hand calculating mileage over 5 tanks of gas, and all highway driving. 2013 JKUS

First leg: Orlando, Fla. ---> Palm Beach, Fla. (I-95) tire pressure 39psi, average mileage 21.1mpg, average speed 74mph (according to GPS after reset), temperature ~81deg.

Second leg: Palm Beach, Fla. ---> Orlando, Fla. (Fla. Turnnpike) fresh tank of gas, tire pressure 40psi, average mileage 16.8mpg, average speed 77mph (according to GPS after reset), temp dropped from 79deg to 47deg along the way - after doing the calculation I assumed I got a "bad tank" from BP, I usually don't fill up at BP..

Third leg: Orlando, Fla. ---> Washington D.C. (I-4 and I-95, multiple tanks) straight through 11hours
(First tank) tire pressure 41psi average mileage 20.8mpg (supporting my thought of bad BP gas - or so I thought), average speed 78mph (according to GPS after reset), temperature ~78 deg,
(Second tank, Georgia) tire pressure 41psi, average mileage 17.4mpg, average speed 78mph (according to GPS after reset), temp drastically fluctuated from Ga. through S.C. to the next fill in N.C (N.C. Was 43deg). Oddly enough this is where I watched the EVIC in awe. I had the avg MPG up so I could compare against hand calc - as I made my way from warmer temps to cooler temps, the EVIC started counting down every couple of min. Going from 22mpg to 18mpg, also decided to look at the TPMS and pressure fell from 41psi to 38psi
(Third tank) tire pressure 38psi, average mileage 18.1mpg, average speed 75mph (on cruise control, according to GPS after reset), temp fluctuation from 43deg to 32deg

Thought this was an interesting degradation on mileage based on the outside temps.. I realize all the factors here, cooler dense air, brick profile of the vehicle and psi drop on tires caused this, I just did not think it would be that significant.. Moreover, a drop from an average speed of 78 to 75 would effect a 0.7mpg increase..