You must drive only down hill. I've never seen 18 or 21 let alone even 16. My best is 13-14 on most good days. 488's and 35's. Do you drive over 40?

 

19mpg with 33s and 3.21 gearing. Highway going 65 max. Best I ever got was 24.5 stock.

2 inch lift, bumpers, intake, and exhaust

 

Drove to Richmond Va. a few weeks ago about 65 miles one way doing about 70 I was getting 24-25 mpg. Stock 2011 sport S with 321 gears and 32's from the factory. I wanting to go to 33 or 35'S dont know what it will do to my mpg.

 

3.73 gears with stock tires and heavy armour I was getting 19-20 mixed driving and now with 37s I get 15.5-16.5 mixed driving

 

35's MTRK's, 3.73 gears, I get 12's in city and 19's hwy with OD off and CC set at 60-63 mph.

 

Mine is a 2007 JKU auto with 4:10 gears. I installed a LoD full-width front bumper, winch, or-fab gas can carrier and a RR light bar.

If I run the stock Good-Year 32 SRA The city mileage stays around 14mpg and highway around 19mpg.

If I put the 35in BFGs set the mileage drops to about 11mpg in city and 15mpg highway.

Did not note difference between soft or hard top.

 

That cold air intake looks like more of a hot air intake.

Stock 2010 mountain. 3.23s, 6 speed, hard top, on stock 32's gets 22mpg

 

Well yeah its not ram air intake but dose its job sounds pretty badass! Plus mu filter has a splash guard so helps keep it from sucking up water if splashed up there.

 

I have a 2008 JKU with 34-ish tires (285/75), and I was getting only 13 in the city and 14-15 on the highway, then recently I made three changes: (1) installed the new Rugged Ridge snorkel (with the extended intake, so it serves kind of like a ram air intake, I guess); (2) switched to synthetic oil; and (3) replaced the stock air filter with an aFe dry high volume air filter. At first my mileage actually went down, to below 12 mpg in the city, and a couple of weeks ago I went on my first long-mileage trip (to a Jeep Jamboree in Colorado), and at first my highway mpg struggled to get toward 13, but suddenly, after about 300-400 miles, the mileage started making rather dramatic (to me) improvements. By the time I got to Colorado, my mileage was about 16 (even in the mountains!), and by the time I got back to Houston, it was pushing 17 mpg (granted, it was "downhill" much of the way). Now after a couple of weeks of city driving again, it's settled down at 14.4 mpg, not great, but much better than the 12 or less I was getting before.

I don't know what caused the sudden improvement on the highway. Maybe the sensors/computer in the Jeep suddenly realized that I'd made the changes described above and decided it could cut back on the gas.

 

2012 JKR stock. Auto w/4.10's. Mostly highway 65-80 MPH, little city stopped to 40 MPH, I average 16.5-17 MPG and seem to do best at 45-55 mph. Removed back seat and put in K&N air filter, 17-18 MPG.

My goal is 20 MPG, maybe swap all fluids to synthetic or not play the radio...