With my supercharged '09 challenger SRT8 6-speed manual I get around 15-16 around town (yes, I can do a whole lot worse than that haha) with a little mixed highway in there (my brother's shop is 30 miles away), and 23-24 mpg on the freeway cruising anywhere from 65-75 mph (depending on limit). Same as it was before I added the vortech V3 supercharger So I'm happy with that!