These are two separate applications. VW's 502.00 is for gasoline engines. Their 507.00 is for DPF equipped diesel engines. Somewhere in there were a couple of gasoline engines that required the previous 505.01 standard which was also a diesel specification. The fuel type of the engine makes a huge difference on the oil recommendation. The reactive by-product is completely different.
Whew,,VW keeps you busy trying to follow their norms. It's no wonder even the dealerships struggle with trying to provide the proper chemicals. I currently require a 507.00 oil but I think I'm going to modify my requirement once the warranty is completely gone on my exhaust system. I prefer the 5W-40 that Mercedes-Benz specifies for their DPF equipped vehicles so I'm likely going to go that route.
505.01 is the fixed interval PD engine oil spec bud, it has no application for petrol engines, 502.00 is the fixed interval petrol engine oil spec. 507.00 is the variable service low saps diesel oil and 504.00 is the variable service petrol engine spec.
I really wouldn't use the MB dpf oil for VW engines as they are completely different engine technologies, just because it has MB approval doesn't mean it's better than a VW spec in fact i think the reverse is true. Almost all fixed interval VW spec (502.00 505.01 505.00)5w-30 oils that do not have the VW507.00 504.00 approval have the MB 229.31 229.51 spec but not the other way around. If you have a SOHC diesel engine defo only use the VW approved oil otherwise say goodbye to your camshaft in 80 - 100 k.
hope this helps
Hi-po petrol, the RS6, specs 505.01.
http://forums.audiworld.com/showthread.php?t=2596395
Must be something quirky with that engine because VW505.01 is definately the PD engine spec