I've been using M1 on and off for decades. I despise it. Since the mid 80s. Had several bad experiences. I don't know why I keep trying that junk out. I guess I'm incredibly stupid. Just when I figure it's probably OK again, a new reason not to trust EVER the stuff comes along.
M1 trashed two valvetrains I had in the mid 90s. Blew out three main seals. trashed a friends Cessna motor. Turned immediately black after an oil change and ruined a car sale (was known to do this in their mid-2000s formulation), etc, etc.
M1 has the best marketing PR machine though.
Wow! That's a load of accusations all rolled up into one large complaint. A product that is high-performing for (literally) millions of other users somehow ruined all that stuff? I would caution you ... when you drop unbelievable claims onto a website where many of the members are very adept at discerning bovine manure, you're not likely to fare well in your fight.
You've laid out several whoppers all in one post .... Please defend them:
Tell me ... how does one specific oil product blow out three main seals, whereas some other brand of the same viscosity doesn't?
And, if your claim is accurate ... why was an automotive lubricant in an airplane engine? (that's a disaster waiting to happen if there ever was one)
Further, how does an oil changing color indicate a ruined car sale?
Finally, if M1 has been so bad to you, why do you return to using it "
on and off for decades"? That is, at its core, counterintuitive.
I'm going to need a lot more than just your claims to believe M1 caused those problems you say. I'm going to need good, hard evidence with photos, UOAs, tear-down analysis, etc.
You have every right to make those claims.
And we have every right to doubt your credibility and the accuracy of your claims.