Without naming any products by name, I tested Penzoil against the best oil money can buy. with UOA's. And Penzoil Ultra Platinum had better wear numbers. Then, I searched the net, and all over the place Penzoil Ultra Platinum is having wear numbers lower then other brands. Use your google, search UOA and Penzoil Ultra and see for yourself. The high detergency and clean base is allowing group 4 characteristics. Look it up, this GtL process puts the base oil in between group 3 and 4 oil, it is in a class of it's own. You get the benefits of group 4 without the risk to seals and gaskets. My engine ran so smooth on the stuff it is like butter. I think PUP is the best oil made. Wished more places would carry it.