Originally Posted by marchyman
Not to be nit picky or anything, but you probably want to add the "JASO MA2" part, also. JASO MB and bikes with a wet clutch really don't go together.
That is correct but there are plenty of oils that are not JASO rated at all that are excellent for motorcycles. Oil manufacturers have to pay for that API rating AND for JASO. If you get a quart/liter of oil and it does not have the ILSAK starburst, "Energy Conserving" in the API bulls eye, and DOES NOT HAVE the JASO rating, it still is most likely good enough for government work. It is definitely OK in an air cooled GS. To beat a dead horse to death
, if it makes you feel good to spend $10 a qt for mc only oil that says JASO MA2 on it, go for it.