what oil should I use in a VR6 gti 6 speed? I went to the shell station to get the oil changed today because they do oil changes for 20 dollars. He told me since my car was a VW it would cost 50. this is unacceptable so I told him I'd do it myself. anyway, he said I needed a 5w40 oil, I'm not sure so I figured I would post here.