986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Castrol Syntec (5W-40)

blue2000s · 04-30-2009, 09:57 AM

Found my answer:

http://motorcycleinfo.calsci.com/Oils1.html

Castrol's product is a Group III based oil. By the way, when people talk of Mobil 1's formulation change, they are talking about the fact that they went from group IV to group III. Not all Mobil 1 versions are made of the same base stock. I believe the some of the extended products are group IV.

04-30-2009, 09:57 AM	#7
blue2000s Porscheectomy Join Date: Mar 2006 Location: Seattle Area Posts: 3,011	Found my answer: http://motorcycleinfo.calsci.com/Oils1.html Castrol's product is a Group III based oil. By the way, when people talk of Mobil 1's formulation change, they are talking about the fact that they went from group IV to group III. Not all Mobil 1 versions are made of the same base stock. I believe the some of the extended products are group IV. Last edited by blue2000s; 04-30-2009 at 10:08 AM.