Higher octane and usage of additives is a waste of your money as long as your bike is running ok as is. I have had a 2005 C50T with 30,000 miles on it and now own a 2008 C50T with ovr 26,000 miles. My wife has a 2006 C50T with over 12,300 miles and we´ve never felt the need for anything other than regular gas.