My father has a 1997 12 valve 5 speed, and has way more power than my 2001 24 valve 5 speed. As far as I know they are both vintage. His smokes A LOT when shifting and mine doesn't. He was told that his turbo may have been drilled out and that was causing the smoke and extra power. Has anyone heard of this on a 12 valve? Can it be done on the 24 valve? Also, is it normal for a 12 valve to get better MPG than th 24 valves? He will average 19-21 and the best I can get is 17.