Quote:
Originally Posted by johnjzjz
Royal Purple Synthetic - has a short life cycle the agent in it that is released is in a cycle span for a race program, and is no good once its used up - Mobil 1 is the best deal on the market for extended use and lubrication period - jz
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I think that we are talking about the two different blends. Royal Purple that you buy in PEP BOYS is about $7.00 a Quart. There Racing Oil is called XPR, and costs about double that. That's the stuff that you have to change after every race season. The automotive grade is very close to the Mobil 1 in every aspect, including oil changes and the additives that are put into it.