I've never bothered to hand-calculate mileage -- I didn't buy my 370Z base/sport/manual for economy. I drive the snot out of it and the onboard computer says I'm getting 20 mpg and change. Where I live, nothing constitutes "city" driving. I like taking twisty, hill-and-dale backroads to my girlfriend's house, 50-odd miles away, so lots of low gears, shifting and speed changes (heard braking as well as hard accel). I'm happy with the mileage. I only fill it about once a week.

 

lol my gauge thing says 16.9 but that is purely hard city driving. like accelerating on the freeway to 90 mph and then exiting to get food.