Originally Posted by aquariuscsm
I know the add pack got watered down via analyses some years back.
Yes M1 HM use to have elevated levels of ZDDP, now it has the regular ILSAC amount.
It was a sleeper performance oil back then, thicker and with more zinc, now it's just thicker- but still a good oil.
I like M1 10W30 HM as it's rated both SN-Plus and Euro A3/B3