R RD400 Joined Jun 20, 2006 Messages 210 Location SoCal Mar 3, 2010 #21 Thanks for that, dnastrau. The owner's manual for my 1978 motorcycle specifies 90 octane regular; I'm pretty sure it was leaded. It runs best on 91 premium, but I always wondered how the spec compares to octane ratings today.
Thanks for that, dnastrau. The owner's manual for my 1978 motorcycle specifies 90 octane regular; I'm pretty sure it was leaded. It runs best on 91 premium, but I always wondered how the spec compares to octane ratings today.
