I was a sheep, and went and bought a 1999 Honda Accord. I made this choice mainly, because it was a mid-size 4 cylinder, that got good fuel economy ratings.

Rated at 20 city and 28 highway, I'm currently averaging about 19 mpg...
I'm not a terribly aggressive driver, there's no leaks or anything(As far as I can tell)... The only thing I can think of that might be hurting fuel economy is the wheels that the prior owner put on. They're 16-inch rims, while the factory rims were 15" in diameter. I never thought when buying the car, that a 1-inch increase would hurt fuel efficiency so much.

Does anybody know what could be causing this dismal fuel economy?