I would suggest not swapping the grade.
GM spec DEXOS 0W20 for a reason, the best thing you can do is keep the oil fresh with a high quality oil and filter.
I would not be surprised if some DEXOS 0W20 motor oils are better than others - they're not all identical.
Problem is oil manufacturers intentionally obfuscate.
How does one know if one DEXOS 0W20 motor oil is ACTUALLY better than another?
Considering GM's error in recommended oil change interval
NOT an error, it's intentional. If we were still changing oil every 3000 miles, engines would last too much longer.
Who really thinks GM wants all their engines to go 200,000 miles without any issues?
and running their transmissions too hot
Bet running the ATF hotter is worth 1 or 2MpG for the CAFE tests.
And again, a transmission that lasts 200,000 miles? Bad for GM's bottom line.
questioning GM's recommended oil weight is valid imo.
Has anyone tried running a different weight?
0W30?
Which 0W30 comes closest to meeting DEXOS Gen3 standards?