Hello forum, Long-time reader, first-time poster. I drive an '02 Acura RSX Type-S, and I'm trying to squeeze every bit of engine life, power, and fuel economy out of it that I can. First car I've ever bought with a loan and I want it to be worth the money Anyway, I'm not going to ask for specifics, because from what I understand (correct me if I'm wrong) usually if you're getting the oil that provides the best protection, you aren't getting the one that provides the best power/fuel economy. What I'm looking for is a list of which oils I can buy that are true Group IV oils - not extra-extra-processed dino oil, like what they market in this wonderful country as "full synthetic". Would I be correct in saying that AMSOIL, Royal Purple, and Castrol's new Edge line are all Group IV? EDIT: Just found Schaeffer and I'd like to add that to the list in that last sentence. I'd also like to add another question - which of these contain molybdenum? I do have a bit of blow-by and I'm thinking that might help take care of it.