If you do use c9 mix it with REGULAR gas. Premium will keep the octane SO high it may cause misfires in the cylinder, and backfiring in the pipe. you need to 'buffer ' the octane in the C9. A ratio of 1 part c9 to 3 parts 87oct (regular) will give you a usable street fuel with a little extra zip! I gained this info from a Yamaha Factory race mechanic friend. If you can tolerate the hassle it will pay of in better performance, and MPG.
Beware the Flat-Earthers.