RP PCMO's are API approved and apparently GM4718M approved, but that's the full extent of independent approvals and certifications that they carry.
Last I saw from GM, RP is nowhere to be found on the GM4718M list - not even on the conventional-level GM6094M list - at least other synthetics that claim GM4718M w/o being on the independently validated list show up as independently validated as GM6094M level performance.
At least the 15W-40 is still a PAO blend.
I cited that since the GM4718M is reportedly listed on their oils bottles. It may be true, since the GM4718M spec seems to be somewhat unique in that you can actually buy the paper which details the requirements and are not reliant on manufacturer testing. If that's the case, it would be possible for RP to verify the oil meets the standard without having the official GM blessing.
while you can buy the paper (i have) which details the testing, if you read it you will find that you have to submit the results to GM for approval, it has to be done through one of their labs, any changes have to be submitted, etc.
if Good Mother doesn't show it on the GM4718M list, it ain't approved, no matter what it says on the bottle. probably the famous "meets or exceeds" verbage.
Totally agree with you. I was just looking to explain why RP can reliably state "meets GM4718M specifications" without actually stating "has GM approval"