Luxter

Correct, Exxon reformualted M1 0W-40 with what's called Visom Group III+ base quite some time ago. There is Exxon presentation floating around the Internet that deals with it. Apparently global PAO supply is not sufficient and costs more.

Suns_PSD

Either way, I've never heard of any engine oil related failure or even damage that can be attributed to any modern oil, even more so w/ a synthetic.

So ultimately, all of the major brands of synthetic will work above and beyond our needs.

I love the statement "Been running brand X oil for 15K miles and haven't had a problem! I recommend it!" LOL. Yah my mom could say the same about running the cheapest oil available and not changing her oil for 20K miles. and getting 200K out of her engine.