Yes.....air cooled.....but at 7k feet elevation.
Haven't tested it.... but change it out 1 time a year and it seems to be rocking along.
Yeah, I know....not scientific....but not burning oil and keeps working smoothly......and cutting grass!
I would say something like "drastic, massive, unnecessary overkill for lawn equipment..." but given that the price of M1 0w40 is down at the same level as the synthetic 5w40 HDEOs like T6... why the heck not? As someone said a few years ago, its just about as close as anyone has come to a universal engine oil. ITs NOT... I still use 0w20 and 0w30 where called for. But whenever I go "off recommendation" for any reason (such as my rebuilds of vintage engines) I typically go with M1 0w40. Except for the Jeep 4.0- I started it on T6 and its doing so well I'm not changing.