Don't believe everythign you hear. There used to be a local guy to me that put the M12 in, real world results for hmi about a .2 and 3 mph gain immediate gain with no other changes.

Don't belive all the internet haters on this swap, sure the 3-4 maybe not the perfect deal but on the track, it works, especially if you have a heavy car (over 3200 lbs)