[RKDinOKC]

People get so political about the brand of oil they use. Back in the mid 90's my mechanic said you could change oils and brands to something different every oil change and it would make no difference. Then later he told me he was seeing a lot of 911s with problems caused by bad oil that were using Castrol. At that time I was running Pennzoil Longlife 15w40 in my 944Turbo. He also said I could run synthetic like Mobile 1, but would just be pouring money down the drain, literal, especially if I observed the recommended 3000 mile oil change on the 951.

I currently use and have been using Royal Purple HPC 20w50 in my GTS. It doesn't see the temps of the turbo like the 951 and oil changes are recommended at 7500 miles. When the cam gear broke off and I rebuilt the motor it all looked brand new including the hydralic lifters and cams. Put in a used set of hotter cams and kept the lifters.

Been thinking of switching from Royal Purple to Amzoil as several 928 owner claim it's antifoaming keeps the idle oil pressure higher when hot due to less aeration. But it's awfully convenient the local OReilys parts store keeps the Royal Purple in stock.