For whatever reason, jeeps are underpowered, at least most are. Somebody thought it was a good idea to put a v6 in a vehicle that should have a v8. Even the old straight six would've been better. Add a gear ratio that keeps the engine rpm's too low and the result's are low power and low gas mileage. I don't live in the mountains but I've towed my popup camper (2000 lbs empty) behind a fully loaded and occupied KK and it wouldn't get out if it's own way. I lifted it and put on 245/75-16 tires and that made the valves ping while going up small hills. I regeared from 3.73 to 4.10 and the power issue is totally gone. The mileage hasn't gotten any better though and I expected it to.
2010 KK Sport, Detoures Knucklebone & backbone, smittybilt XRC 10, rigid led lights, R/L sliders & rack, cb, EMT2, R/K 15x7, OME, JBA, mopar skids & hitch, headlight covers, 4.10's and TruTracs