Originally Posted by cv129

I have m1 0w40. This is synthetic under the euro standard, not the same as the US standard.

This is GTR's factory fill.
Great UOA's are the quantitative proof.
Nissan "ester" oil is just normal non-syn oil with ester additive to quiet down the vvel. I remembered reading about poor UOA's in vq37 application.

If weight is an issue, "German Castro" 5w30 is excellent. Redline 5w30 is another good one.

But oil is like a voodoo topic, some feel better to just stick with what manufacturer says, others rely on UOA's, just do whatever you want.

If your oil change interval is not too long, exercise precaution on cold start, and normal driving takes up 99.9 percent of the miles on your odo, result of this debate won't matter too much I think.