Checking in again after a weekend trip to Houston, TX. 12.99 gallons got me 590.5 miles in my 2009 Civic LX (automatic), for an average of 45.458 mpg. About 550 miles of this was highway driving, at speeds of 50-60 mph (depending on weather, road conditions, traffic flow, etc), with about 40 miles of city driving thrown in (I get about the advertised 25 mpg in the city). I have my iDrive55 window cling posted on my rear driver's side window for passing cars to see.

Kate H., Baton Rouge, LA