Are you able to provide some specific info that says M1 HM has the ability to clean an engine? Since M1 makes HM oils in a couple of flavors, which HM are you referencing?
What motor oil does the best job of cleaning?
I'm going with the one changed regularly Alex for $1000 please. ;) That's the Daily Double. What is, "Esters have desirable cleaning properties as well."
bobistheoilguy.com
See post#56 and #57, In 57 I include a screen shot from the Mobil 1 HM jug.