Regarding M1 you're right for the US web site, but canadian site doesn't list HTHS.
Nor do Shell, Esso, Petro-Canada, etc. Even for their synthetics.
Anybody has an idea for Esso XD-3 0W-30?
Since it is a robust 0W-30, I would guess closer to 4 than 3?
Palut had found the HT/HS numbers I was looking for in this resurected topic just below;
"Thanks guys. I called Esso to get the 0W-30 HT/HS, and asked about the 0W-40 to make sure it hadn't changed. The guy said that the 0W-30's HT/HS is 3.6, and the 0W-40 is 4.2 (just like you said Jaj). The 0W-30 sounds like a very good oil for that weight."