I totally agree with you dolt that the rating is a base standard but which oil is the base and which is the best?? In this post alone there has been recommended multiple different brands and weights of oil so which one of these api.sm rated synthetic oils is the best?? Prolly no answer here!! Now if one oil co. invests in a test that ups their oil to a api.sn rating then we might be a little closer to a definitive answer.But then again all the other companies would rush to have their oil rated api.sn too. Then we'd be back with which meets the standard and which is the standard?? Two sides and no answer.