Are you referring to his stating the tach ran lower for the same speed? I think the reasoning would be without burning the garbage that usually comes through, only buring the more combustable gasses, it would burn/run more efficiently, giving you the same power with less throttle but I can see your point. This guy is one of the best shade tree mechanics around. He wouldn't be fooled by hype, plus he's a school teacher with a large family, he is very careful about how he spends his money. He wouldn't drop it on something that he didn't think made sense. Do you know anyone who has used a PCV canister?