Actually, the burden of proof (or integrity) is placed upon the shoulders of the lube marketer, not someone viewing a public approval list and cross referencing it with an owners manual.
Claiming the spec in one spot, not claiming it in another, and validating that the spec stewarding OEM has not independently validated performance is a perplexing combination - especially for a well known brand such as Valvoline.
Nobody is saying that it's not a good oil. On the GM note, GM has indeed validated it's performance to grant it the conventional-level GM6904M spec approval. Based on this, it appears that Valvoline has indeed been in contact with GM regarding Synpower performance.
IF Synpower has indeed taken the tests to prove GM4718M minimum performance and passed, and Valv has chosen NOT to truthfully claim that performance level - it makes no sense, nobody would do this. Valv truthfully obtains and displays approvals for many smaller market share companies, why not for the 2nd largest OEM in America? Independently validated minimum specs hurdles exist so you don't have to decide whether or not to believe an oil sales pitch.
Valv is not alone, Castrol Syntec is in the same boat too - not GM4718M approved either, but it indeed has the conventional-level GM6094M spec that GTX doesn't even carry anymore after GM's recent removal of GTX from the GM6094-approved list.
If a company is confident their product has GM4718M performance, how do they know if they haven't taken the tests? If they have taken the tests and passed, they would surely present the data and gain approval in a heartbeat. Claiming a spec without validation doesn't add up.
