This is interesting. I had my longlife service a few months ago and noticed the oil had changed from 0/30 to 5/30. I feel suspicious why and whether the Castrol 5/30 is longlife oil for a PD engine and not the fixed service oil.Should be a sticker under your bonnet, at the front, near the latch. Mine (2005 car 2006 model year) says:
Long Life Servicing
Use Castrol SLX LONGLIFE II (As printed)
I know you can't get Longlife II anymore, so I'd guess that the standards numbers at the bottom are the best guide.
As MattsBlackGT says though, the recommended grade may have changed, but,don't the grade numbers indicate the range of temperatures over which an oil is effective? As I understand it, an oil rated 5W-30 has the same upper temperature limit as one rated 0W-30, but will not be as effective at lower temperatures. The oils may well be equivalent in all other respects, and meet VW's specification for the long life service regime.
Most of the oil they sell will be as part of a service, when they will charge ?50+ for it. This will cost them nothing like that figure, as it will be bulk supply, in a barrel. As they would be on thin ice, charging two prices, they will stick with the higher one. They are not called stealers for nothing.I can not understand why V W Dealers are so bad at pricing ,If they sold the correct oil at a good price there customers would buy it instead of going elesware.
The EDGE 5W-30 meets the latest LongLife III specifications ( 504 00 / 507 00 ) and is backwards compatible with LongLife II so VW dealers will now be using the latest LongLife III specifications in place of the LongLife II and this is quite acceptable.
LongLife III supersedes the LongLife II in all but some R5 engines and is miscible with LongLife II so you can use for top up and refill
Lubricants Automotive - Europe Region
Lubricants Technical Advisor