Maxx, I was watching one of those car shows on Spike TV on Saturdays a couple of weeks ago and they did a dyno test using standard lubricnats (engine/trans/rear end) then ran a second test after changing all lubricnats to a synthetic (the purple one, don't remember the name) Amazingly they had about 10 HP more (if memory serves). So it looks like the stuff really does reduce friction significantly. But to get that kind of advantage you would have to replace all your lubricants not just the engine, but since it really looks like the stuff works, even only changing your engine oil should be some advantage.