What are your thoughts on M1 0w-40? The oil has shown to shear down to a high 30wt oil many times. While it would thicken back up over time do to oxidation, some don't like it bc it does shear. Wear metals are so so and usually your 5w-40's show better results.
IMO, this oil tries to be a one size fits all and with that makes some compromises. It's now SM rated. Your 5w-40's are usually loaded with more ZDDP also. Someone mentioned cleaning ability and that is why it shows higher wear metals. I don't buy that being other ester based oils like D1/M1 SUV show better results. Thoughts?
Oh and the argument that it comes factory fill in high end cars is a good point, but most of those cars hold 9 qts of oil so I'm not really impressed by that fact.