I switched to a new dealer for servicing and they used Castrol Magnatec 5W-40 full synthetic, whereas the previous dealer used Castrol Edge Professional 5W-40 which is also a full synthetic oil.
I like to keep a litre or two (OK, quart) of oil available and wanted to buy same - only to find that there are two different specification Castrol Magnetec 5W40 oils available - one with a A3/B4 specification and the other with a C3 specification. The dealer is not very helpful as they buy bulk in 44 gallon quantities and does not seem to know which specification it is, hence my cry for help. The Castrol web site also does not help as it indicates a "special formulation" for this model.
Which one is the correct one for my car? For clarification it is the 210kW / 265 hp engine and not the more powerful one fitted from late 2011 onward.