0W-40 is definetly too thin for higher mileage cars, I don't plan on using it in my Benz. I may at some point, use it in my VW. Around here in NJ the Synpower I use is not readily available. I have to go to NAPA and order it. It doesn't cost anymore or less than Mobil 1. It cost me $4.69 a quart. At this point, NAPA and other auto stores don't have this weight on their shelves. I have read on another message board, VW Vortex, that Synpower 5W-40 is on the shelf out west. It usually takes 2 weeks for the oil to come in, so I once ordered 2 cases (12 quarts), just to stock up. Once I use that oil up I may try Mobil 1 0W-40, IF the local stores have it on their shelves.
Ymsin, I don't recall Castrol having a "0" oil.
There were many comments in past "oil" threads about wishing for Mobil 1 to bring over their 0W-40, so when I happened to find this info. on their website, I thought I would let people know.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section