[Jeff Higgins]

I used Harley-Davidson 20W-50 in my Beetles for 30 years without issue. They have synthetic and dyno, I just used the dyno. In a large part because I always have it on hand, and it's really easy to find on the road away from home. And, being motorcycle specific, it is not beholden to the regulations lowering ZDDP content. Of course newer Harleys now have CATs, so I'm not sure how that has affected their oil. I'm told it is still useable in all older Harleys, but they have always had roller tappets anyway, so I'm not sure how important they consider ZDDP content to be. It is still recommended for use in their older transmissions, though, so it must still retain the higher shear strength needed in that application. I did continue to run it in my last Beetle for about 5-6 years after Harley added CATs to their touring bikes, if that means anything.