Threads like this make me realize how lucky I am when it comes to gas mileage. My 652 hp Callaway Z06 gets 28mpg on the highway and even averages about 18mpg. Point being you do not or should not need to sacrifice fuel economy when it comes to performance. My Viper is probably closer to what you get. Even the wifes 335i gets worst gas mileage than my Supercharged LS7.