With about an even mix of highway and city driving mine is getting 17.8. I just thought that seemed a bit low. The only mod the car has (that I know of) is a K&N Air Charger intake. I'm wondering if I put the stock intake back in if it would do any better. It only has 3,000 some miles on it. Maybe it will due better when it gets more broke in. And yes, I know this is a sports/muscle/pony car and not an econo box