Well, since the last time I used Pennzoil and jumped through all their hoops for the rebate, and since they refused to send me my rebate, I will NEVER EVER UNDER ANY CIRCUMSTANCES EVER BUY ANY PENNZOIL PRODUCT. Also, no Valvoline, a while back I talked with a large rebuilder of engines north of Detroit and asked him if he had noticed any particular oil that seemed to result in a blown up or worn out engine. He said "Funny you should mention, but the great majority of the bad engines that come through here have used Valvoline." I do like Mobil 1.