I wholeheartedly disagree with the nay sayers on this one. MMO is the best thing you can do for your car. Added to the fuel supply, it acts the same as the "detergent" that all oil companies put in their pump gas. It will keep down carbon deposits on pistons, heads and plugs.

I has been long used in the aviation community as a gas additive to keep engines in pristine working order and prevent spark plug fouling. Do a search on the internet and you'll find very compelling evidence of its advantage...