Most of my driving is on highway to work, but I usually average between 80mph. It is only 25 miles for me one way, but I don't go to redline between lights, just when I accelerate on highway in 1st and 2nd gear. I usually can go at least 300 on a tank with the A/C on averaging 26mpg. At least 330 with out a/c averaging 30+mpg. When I get on it often in all gears my gas mileage drops quick.
My car is stock except for a Thermal exhaust which I hate(too loud). I want a nice quiet sleeper, but need $$!!