I compiled a spreadsheet of my MPG's from basically January to April 2006. My average is 20.12 MPG, with a peak of around 21.6 MPG and a low of around 19. If interested I can pull the data to get actual numbers.

What's interesting is that while the price of gas has gone up since January, my MPG averages have gone down... So I'm increasingly paying more for fewer miles between refills.

I drive a 2005 6-speed M/T. I drive about 50/50 city / highway. Guessing that city driving averages around 40 MPH at 1500 RPM's flat. Highway is around 70 MPH at +/- 2000 RPM's flat. I use 87 regular (Texas) from Racetrac and QT gas stations.