As I said, if you put your trust in your garage, as you might expect to do if you pay full labour and parts prices at a franchised garage, you in turn expect them to use their sense about such things. With all the various problems that have surfaced with the DSG transmissions, were they going to wait another eight or nine years for you to hit the official 40,000 miles before they suggested that you should have a DSG oil service? It’s most surprising though that there apparently is no official time based interval for this service, as I have now discovered, and as there obviously should be!
Reference engine oils in small one-litre packs, these are nearly always something of a rip-off, and mostly sold to desperate drivers at roadside filling stations, and at a very nice profit margin. Petronas are a respectable Malaysian oil company, and are known primarily as sponsors of the Mercedes F1 team. I think I had presumed for some years that they were a Spanish bank, or something like that. Having looked more deeply into it now, I don’t think there’s any good reason why you should not use this Petronas product, as all these ACEA and manufacturer listed oils have to pass tough tests to receive approval. I guess that Petronas have done a deal with Euro Car Parts that avoids expensive advertising and allows them to sell it relatively cheaply. You want the Syntium 5000 AV 5W-30, which meets the VW 504/507 specifications. Similar grade oils Syntium 3000 and 7000 are specified by Mercedes-Benz, which I think should assure us pretty well of their good pedigree.