Arduous > grueling > laborious > strenuous haha
So no other oil spec can meet those onerous demands ? Curious when VW502 was made. Early 2000's ? So it's quite possible we've advanced enough to protect with
superior blends, meeting higher # VW spec and able to deal with Arduous situations ?
What's missing from these is the oil change interval recommendation at the time they were made. VW 502 was for how long ? 5k miles ?
Also 502 replaced 500 and 501 which used an “old” oil specification from the 90's.
Or was 503 made for those "extended" 10k runs ? Then 503.01 was made for an even higher demand
yet both are superseded by a superior blend >
VW504
VW 502.00
Oil for gasoline engines. Successor of VW 501.01 and VW 500.00 specification. Recommended for those which are subject to arduous conditions. It must not be used for any engines with variable service intervals or any which are referred to under other specifications.
VW 503.00
Long-life gasoline engine oil for VW cars with WIV (system for longer service intervals). Also meets ACEA A1, SAE 0W-30 or 5W-30 specification.
VW 503.01
This specification is specifically for Audi RS4, Audi TT, S3 and Audi A8 6.0 V12 models with outputs of more than 180bhp, running with variable service intervals (30,000km or 2 years). Now superceeded by the VW 504.00 specification.
VW 504.00
The VW 504 00 specification superceedes the VW 503 00 and VW 503.01 specifications. VW 504 00 oils are suitable for engines meeting the demands of Euro IV emissions standards.
VW 505.00
Passenger car diesel engine oil specification, minimum performance level CCMC PD-2. Lists viscosities SAE 5W-50, 10W-50/60, 15W-40/50, 20W-40/50 requiring 13% max. evaporation loss and SAE
5W-30/40, 10W-30/40 requiring 15% max. evaporation loss.
5w-40 weight is in my car, but if I need to change my oil during or before winter, it'll be a high VW spec 30w oil. FYI, There are 0w-30 weight oils that meet VW 502. In fact, most oils that meet VW502 meet VW 505. Just like 504/507. Many feel strongly that a hard running motor needs a thicker oil. But if the oil specs improve and a manufacturer says it's ok. Well ? They would know, no ?
Notice VW 508/509 are 0w-20 and ok for diesels. Thinner is coming

.........VW is just slow to change !