That's not what I'm talking about. I'm talking about the differences between the oil chart from 2016 versus the one in this post. There's a half dozen new oil grades which aren't CAFE oils on your chart. All of a sudden Mazda is giving its blessing for these grades.We are all well aware, what's stated in the owners manual is regulated by CAFE for 0.2mpg fuel savings, NOT based on what the engineers designed the vehicle around.
It's helpful to know what the engine is actually specified for, and , to consider the statement: "tight engine tolerances" as complete and utter bull, and to stop worrying about using 5w30 when the engine was clearly designed for weights beyond that. 5w30 is also a weight that was pushed by CAFE not very long ago, actually.
As for actually going beyond 5w30? I'd run 5w40 or even a 10W in hot weather. Done it before, would do it again.
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