I got 25 highway from a recent trip down to orlando from atlanta. no traffic, flat road and I was using cruise control for hours. I got like 340 miles off a tank...and I was refilling somewhere in the 14-15 gallon range....so like 340/14 = 24.2, or maybe 340/15=22.67 at the worst

...so sue me for my significant figures but its in the ballpark. I just figured the city the other day and it was like exactly 16.0...kinda funny.