Mobil 1 Turbo Diesel Truck does not carry the 505.01, 506.01, nor 507.00 VW approval. Yet there seem to be UOA's surfacing from use in pumpe duese (model yr '04 - '06) Volkswagen TDI's that seem to show it may offer reduced wear vs VW spec 505.01 oils. It also has a lot of Zinc and Phosphorous that may benefit the flat tappet design of the PD's cam and followers. Plus, its a robust 5W40 whereas some of the VW spec oils have gone to 5W30. But then there's the long term effect of M1 TDT's increased phoshorous content on the TDI's catalytic converter. Interesting.