"This is a worthless thing.
Its like saying "What oil viscosity is best?"
It depends on the application.
Many wont work *AT ALL* in some applications.
For example none on the list would work in a subaru MT.
You would want redline 75w90NS not the redline MT series."
You're partially correct- the question "which oil viscosity is best?" is a good example of the conversation I am trying to have. They're all different, have pros and cons etc- so what are those advantages/disadvantages? So without a specific application in mind how do we elucidate their attributes?
5w30 is great for x, not suitable for y.
10w-40 is.....
Rather complicated for engine oil but in the much narrower field of modern manual transmission fluids could be a useful guide for people like myself who don't know as much as others.
Thanks to all for the replies so far.
