Thought I'd try V power.

[Simon.Pieman]

Just to make a bald statement saying what everyone else had said is cobblers, without giving any reasons even for that statement, well, not surprising you'll put someone's back up a bit, is it?

There you go again, I did not say that what everyone else said was cobblers, I did not use the word 'everyone' or infer it, yet another misrepresentation. I said there was 'cobblers being said about these fuels' and there ARE comments that presume these fuels perform better because of a higher RON value -you do not have to be engineer to work out that an anti-knock additive is in a fuel to retard the burn in engines that need it, and patently does not offer any advantage in engines that don't need it (like in a standard jap four for example).
Sorry if I appear arrogant but perhaps I should have mentioned relevent credentials, I was a marine engineer (with a good degree) for 35 years and taught it at City of London Poly for 3 of those years before moving into diving tech. I do know a little bit about engines and the stuff that makes the bits move around inside. I don't know what Shell stick in their fuels but I'd bet the bottom line is that your engine runs just as fine without it.