With all due respect Henry, even at 65 mph, 15 mph is optimistic. Perhaps if your engine is down tuned, your tires are at 36 lbs, your foot is light, you cruise at 45 mph and never hit the brakes, but realistically, who does that anyway? I start the engine, goose the pedal to hear the rap, wind out the gears, compression brake to rap it again, hey, this is fun! Who cares about mpg unless your gas gage is broke?
