would like to know what the mileage your getting with your jks.Gears tire size and mods would help me in a direction .I have 37s 513s auto getting 12.4 is this about right about 460ft above sealevel. Can't even get 300 miles a tank. I know it won't be good but 12.4 and no power at all is about to wear me out.

 

auto with 37s and 5.13 and Im getting 14.5 city and 15.5 highway at 5000ft. I have an AFE CAI along with a Flowmaster 50 series muffler and a hypertech max set to premium.

 

5.13's
Cooper STT 37's (36.25" actual)
430ft or so elevation
Airraid CAI
Magnaflow 4"x18" muffler
Superchips programmer on 87 octane
Mostly city style driving

I get 14mpg. I am really gentle on the skinny, no quick starts, hardly ever get over 65mph.

I haven't taken a longer trip on the highway but last 30 mi Interstate drive @ 60mph computer showing 17.4 mpg.