I used Motul 8100 x-cess 5w40 for a couple oil changes and for the most recent one, I switched to Castrol Syntec 5w40. The Motul was fine in my 03 GTI VR6, but I figure for the winter, I could use something cheaper, since the Motul is a good chunk of change more than the Syntec. After doing some lurking here, I learned that the Syntec is a group III, so I'm thinking about switching to something group IV, which leads to my noob question and threadjack (sorry!). I was wondering if Motul 8100 x-cess is a group IV oil? Is there actually a list somewhere of which motor oils are group III and IV etc?