well I just burned up a whole tank of gas just driving from home to work in almost 2 weeks.. I didnt do any hard driving. I averaged maybe 35-40 mph and didnt go over 2.5k rpm and only did 360 miles till the fuel light came on. so I averaged 17mpg... if i remember a full tank is 21gallons? Anyone else average about the same? I used 89 octane... can grade of gas affect it in anyway? im about to go fill up with supreme now. The gas prices have dropped $.10 since I last filled up hehe.