What brand of engine oil does Rosie's Yamaha motorcycle use?
Is Rossi competing for a large-displacement Yamaha motorcycle or a Rossi version of a domestic joint-venture Yamaha motorcycle? If it's a large-displacement motorcycle, it's better to use synthetic engine oil. If it's a joint venture Rossi version of a small-displacement motorcycle, they just have different decals and colors. Just use ordinary mineral engine oil, and any genuine engine oil suitable for motorcycles will do.