Lucas is very popular here in Oregon. I have used in the trans and in the engine. Definately not snake oil. Works very well. Many guys here run it in their trucks and cars and use it all the time. Especially hauling loads or pulling trailers and such. The best thing I have used is System 48 Plus. I have it in my Chevy truck and love it. Had it in my diesel 4x4 Suburban ( which I should have never sold) and it made it turn over faster plus super quiet running and quicker revving. Not a gimmick like many other things are. Even put it in my 94 Bravada with the 4.3 H.O. My friend Paul uses 48 Plus in his old 89 Caravan with the 3.0L Mitsubishi engine. Usually noisey top end and now super smooth and quiet even on the cold mornings. Use to clatter and had valve trane noise. Has 167K on his engine. Zippier too. Can be used in trannies and differentials. Its not Teflon. Its nice to know there are some things that really do work! H.