On Fri, 5 May 2006 11:18:53 +0100, "vortex2"
wrote:

I'm nearly convinced. Is there any negative side to running higher octane
fuel in your engine?

Yes, you could be wrecking your engine if the compression ratio can't
take the faster burning fuel. In simple terms, it goes bang faster
than lower octane ratings, so the engine must be flexible enough to
take it.
A look in the data section of the handbook should clarify it.