August 28, 2003I have done some investigation into this on the oil websites, yes they have them.
Amsoil, Mobil 1, either car or v-twin, Syn 3 are made from essentially the same base stock. The Additives are not that much different and all the testing showed that all of them would last an easy 10k (some showed little breakdown at 20k) without breakdown in your aircooled engine. Just change the filter at 5k.
I use Amsoil and Mobil 1 (car oil) in everything. It's my choice since I have been using for years. I don't think you can go wrong with any of them or any other synthetic. They are too much alike.