As a reference point, My 2000 WJ 4.0 got 11 mpg doing my newspaper route, 16 around town, and on a trip to Rochester from Syracuse one hot summer day, it got 26mpg! I did the math by filling it up, zeroing the trip odometer, doing the trip, filling up upon return, and doing the division. The trip was at a constant 70 mph, 90* air temp, No A/C with all 4 windows down, and a basically flat terrain and a constant wind. I spent around 30 minutes driving in Rochester so it could have been higher. Total distance 190 miles. NYS Thruway.