i run klotz...i think that youll find that once people try an oil they stick with it.doesnt matter if its brand a, b, c or d. if they use it and they dont blow an engine up or anything then they consider it to be good oil. now on the other hand if someone blows a motor up using a certain type of oil then they usually blame the oil, and then dont use it anymore. im guessing thats where youll hear most of the bad remarks about whatever type of oil..