My 01 wrangler 4.0 5 speed on 30's? gets about mid 16's to and from work 7 miles one way local roads with lights. 65 mph on the parkway nets just about 20. With the hardtop on for winter, it'll probably drop half an mpg. Roof rack will probably drop another half an mpg but I usually put it on only when needed, like going on safari
