I guess if oil is all the same, then gas is all the same too?? I guess if you change your oil every 3K miles, it doesnt really matter for normal driving. I have used Castrol oil for years (my personal preference, not for arguement sake) and have found that it keeps the engine exceptionally clean. Since I really keep up with changing the oils regularly, any oil would probly have the same result. I watched a demo on oil one day and the rep who handled several lines, cut the oil bottle right above the bottom and let the oil drain away. We all looked at the bottom of the bottle and you would be suprised at the contaminants settling out. The only oils that didnt have this problem were Castrol and Havoline. That reinforced my opinion of Castrol. I burn BP/Amoco fuels (premium when it was affordable) and the combination of these two products have kept me on the road and helped keep my engine's internals clean as a whistle. Just my $.02 <img src="/forums/images/graemlins/notooth.gif" alt="" />