Mobil 1 ESP 0w30 observations

[OVERKILL]

If we are comparing 229.5 for example to 229.51/229.52:
- Stay in grade: same
- Phosphorous: 229.5: up to 1,100ppm, 229.51/52: up to 900ppm
- Magnesium: 229.5: up to 400ppm, 229.51/52: up to 300ppm
- Load carrying capacity: 229.5: 150N, 229.51/52: 100N
- Load carrying capacity, aged: 229.5: 60N, 229.51/52: "rate and report"
- Piston cleanliness: 229.5: 14 merits, 229.51/52: 16 merits
- OM646 biodiesel piston cleanliness: same results
- OM646 wear test: same results
- VW T4 (all parameters from VW 502.00) 229.5: yes, 229.51/52: no
- Daimler LSPI test: Applies to all

So very similar requirements, save that 229.5 has more load carrying capacity as a requirement and the OM646 piston cleanliness requirement (non-biodiesel) is slightly higher for 229.51/52, but is equal under biodiesel, which I think negates that.

The VW specifications are also informative, if we are looking at comparing 502 00/505 00 to 504 00/507 00, they are mostly similar with the exceptions of:
- M271 Sludge test: only applies to 502 00/504 00. 502 00 merits: 9.1, 504 00 merits: 8.5
- VW FSI (DI Gasoline test, intake valve deposit weight): Only applies to 504 00
- VW ICTD piston ring sticking and cleanliness: Only applies to 504 00
- VW TDI (diesel test): Only applies to 505 00/507 00, 505 00 only one with TBN retention requirement
- DPF test: Only applies to 507 00
- Baumusterprufung: RNT wear test only applies to 504 00/507 00, Gasoline Engine tests only apply to 504 00, diesel engine tests only apply to 507 00

So again, very similar. Afton unfortunately doesn't have the Porsche test sequence details, which would be a nice additional data point.