Cosmic Flash,
I have an SAE paper that describes part of the VW 502 testing, which is loosely based on the ACEA A3/B3 specification. I'll post the info when I get the chance. The VW "T-4" test basically involves a 248 hour run in the 2.0L, VW engine under varying loads, and no makeup oil is allowed. There are specific limits for cam/lifter wear, viscosity increase and TBN as I recall. It's a very severe test compared to any of the API engine sequence tests.
Info on the MB 229.5 tests is provided on the Lubrizol.com website ....I've yet to find any available info on the BMW or GM Longlife test requirements.
TS
I have an SAE paper that describes part of the VW 502 testing, which is loosely based on the ACEA A3/B3 specification. I'll post the info when I get the chance. The VW "T-4" test basically involves a 248 hour run in the 2.0L, VW engine under varying loads, and no makeup oil is allowed. There are specific limits for cam/lifter wear, viscosity increase and TBN as I recall. It's a very severe test compared to any of the API engine sequence tests.
Info on the MB 229.5 tests is provided on the Lubrizol.com website ....I've yet to find any available info on the BMW or GM Longlife test requirements.
TS