I tend to agree that miles per tank isn't a good gauge to compare with. MPG's will tell you how you're doing. FWIW, put me down for 23 mpg's mixed driving. Mostly taking it easy with the occasional romp through the 5 forward gears.
Wow, 12+/- i never wait the light LOW FUEL turn ON, ehehe... So i just see 12gallons,lol! Well, my in city just 170miles+/-, how the hell someone can do 400 miles? You sure your engine is v8? LOL!
I just put 89 octane gas, can be this too? ehehe!!
I don't remember the exact ammount I think it was 380 or so, but yeah supercharged and with 3.73s that was my best tank ever. Boring ass drive through TX and into OK stuck behind a flippin RV towing a car for a few hundred miles with no chance to pass.