I have used penzoil aircooled and it works very well. I have also used the mobil 1 synthetic two-cycle oil.

Elson (bugman) is the 3W guy here, he operates a fleet of 3W engines on research planes and has many more hours on these beasts than anyone else. His advice is solid

Yes there are two 3W-60's. The one I have shown is long out of production. The later version is a rear carb with reed block configuration. It is more powerful and heavier, also larger in size than the "K" model.