Viperbob1

15w-50... or... Will not lecture on the low additives now since the Extended Performance Mobil 1 is gone. BUT the Mobil 1 0w-50 Race oil has MORE than u need. This is what using these days for my customers AND for the later cars with IMB potential problems it is cheap insurance.

97_993C2

My 993 has always used Mobil 1 15W50, although it could have used 0W40 during Super Bowl week down here if I had actually wanted to take it out for a spin (literally).

moeck

Do a search on swepco 306 15-40. changes in Mobil one have been noted to cause pre-mature ware in Porsche air cooled moters. Excessive cam waer very notable. There is quite a bit of research out there if you Google it. Heyer Performance switched on me and I was upset until I did the research. Mobil 1 still great but I suggest and you will find major findings why it's bad for air-cooled motors

tctung

I live in Taiwan where the climate is similar to that of Southern Cal. Mobil 1 fully sync 15W50 is definitely better than 0W40.