Originally Posted By: Rolla07
Impossible to prove one is superior. What are we basing it on? Take 2 oils, both completely different specs and compare them. Besides feel what scientific test can be administered to prove superiority. You know why I stick to Mobil and Pennzoil? Reputation. All the marketing costs and ads surely have done the job. They have a great reputation. Is it worth spending 5$more per jug for reputation? I dunno, but it makes me feel better and I have other things Id rather spend time worrying about in life. Would my car know the difference between ST and M1 or PP? Doubt it. I couldnt prove it so clearly beyond feel which is largely subjective, no proof its better or worse. Are all oils the same? Nope, but different doesnt always equal inferior. Can we say valvoline is superior or worse than Pennzoil because they put sodium in their add pack?
I am no motor oil expert (the thought is comical, in fact), but from what I do know, there are scientific tests that can be used to determine if one oil is superior to another in specific applications. Would you run an API SH oil in a 2015 model year turbocharged vehicle that calls for an SN oil? I wouldn't. The differences between those specs are based on required results for various scientific tests. Things like NOACK, viscosity index, shear stability, TBN (initial and retention), etc., can be used to make judgememts between oils, but again, it is all application-specific, hence the guidelines for asking on this forum about which oil should be chosen.