Originally Posted by kschachn
I'll be the contrary voice. Why would you "need" a 0W/5W-30 oil? The only part of that statement that could be a "need" would be the cold weather performance, and then only if you are operating in conditions that are -30F or so. But you are asking for either a 0W or a 5W so that implies you're not looking at extreme cold weather operations.
And as far as the grade, any oil that carries actual 502 00 approval is going to have a minimum HTHS and that will ride the fence of a 30 or 40 grade. This will make either one virtually irrelevant in terms of operating viscosity.
I run "Euro Castrol" 0W-30 in both our BMWs and our VW. Where we live in California gets down to the mid-20's on the coldest of winter nights (and that's rarely) and summer daytime highs sometimes exceed 100 degrees. Furthermore, all my cars are kept in a well insulated garage.
Given all that, I prefer to run 0W-30 instead of 5W-30, 0W-40, or 5W-40. IMO the motors are freer revving. Each one of these oils can meet MB 229.5, BMW LL-01, and VW 502.
Scott