438.6 miles on 5.23 gallons. That's 83.86MPG. I'm pretty happy! I checked somewhere around 3000 miles too, but I was only getting around 65MPG. That was a four tank check too, so these checks should be really accurate. What's changed? I've slowed down a little. I used to always go 50 to 60 traffic permitting, and now do 45 to 50 typically unless the cars around me are going too fast. Also I did my tune up a few hundred miles ago with a new spark plug, and air filter. I adjusted the intake valve just a little bit too.