3g hemi gas mileage

I have an '04 Ram Rumble Bee ( stock 5.7, 5-speed auto, 3.23 rear ) running Super Chips programmer set on Economy 87oct, Flowmaster and rear muffler delete and get 21mpg on freeway at 68mph (1750rpm) and average 14 mpg in town. I was running around on the Performance setting back when gas was under $3 but never checked my fuel milage - it was too much fun to drive and would romp on it all the time, lol.