Originally Posted By: harrydog
Well does that mean that oil can not exceed the minimum requirements needed to meet the approvals?
Of course not. An oil could do significantly better than the limits of the test and get approved. The purpose is that it at least meets those requirements. Overachievement isn't an issue.
Originally Posted By: harrydog
By no means am I implying that the approvals are worthless. Far from it. But just because an oil has gotten the approval from a manufacturer doesn't mean that it is the best oil you can get for that application.
No, but it DOES mean that the oil has been tested and approved for being suitable for that application, which is a heck of a lot better of a start than somebody's marketing claim that it "should" be better
Originally Posted By: harrydog
There are differences among oils that meet the same specs. For example some oils are already good enough to meet the next generation of manufacturers specs while others will need to be reformulated in order to meet them.
This is true, and that's why it is nice to look at an oil that has a myriad of approvals, all of which you know are demanding, as a way of perhaps divining some insight into this.
However, one also must consider that if oil "A" exceeds the performance requirements for your engine, what advantages are you going to see from running oil "B", which exceeds them by a bit more?
That is, if oil "A" is approved and will allow your engine to run happily well past the life of the chassis it is fitted in, the transmission it is mated to and on into the wrecking yard, is concerning yourself over how much better "B" might be over "A" relevant?