Hey guys. All this talk about the new castrol 0w30 and Mobil 1 0w40, I decided to venture out to my local auto zone to see what they had. On the castrol side, only the old yellow castrol 0w30 is there. They had NO clue when I asked about the new german oil. I did see the Mobil 1 0w40. This seems like a pretty interesting oil. You get the best from both worlds, great fuel economy, fast start up flow and the 40 wt for hot summer days. Anyone put this in their cars yet?