I use that GM 5w30 oil too, and recently bought a sealed GM labelled cardboard box of 4 x 5 litres from vauxhall, and inside, instead of the usual GM oil, there were same-design bottles of AC Delco Supreme Longlife III 5W30 which was rated at VW507.00. I can't remember the other ratings, but can post them if interested. The oil is made in Belgium, who makes oil in Belgium? The barcode starts with 54 which is Belgium, so I hope to look at Castrol, Shell etc... to see who else makes it there.
The recomended oil for SWMBO's 2.0 tdi VW Eos is Castrol SLX 5W-30.
This appears to cost a princely £12-50 a litre, so must be something special. :-o)
Am I right that you must use this in a VW PD engine, since it has additives that prevent premature wear of the apparantly narrow cam lobes, forced on the engine design by also having the PD injectors in the head.
Or is this just an urban myth, to make VW money ?
The Castrol Edge 5W/30 meets the latest VW Norm 507.00, for variable servicing intervals, but the very similar sounding Edge 0W/30 doesn't! The point about the PD engine is that the viscosity is secondary to the specification required by VW, unless you want to warranty the engine yourself. Caveat emptor:)