Thanks Dan!
As for the Shell V-Power, higher octane fuels are not strictly more explosive than lower octane fuels, it's that they have been stabilized to avoid early detonation during higher compression. I've read that many high performance engines are designed to run best at the highest octane rating they can get because they adjust the compression to suit the fuel they're using - while sticking high octane fuel in a car like a Robin Reliant will actually slow it down instead of making it faster.
When an engine runs at higher revs, presumably the pistons will compress air/fuel mixtures more quickly prior to ignition. Is it possible that the Shell V-Power is only really efficient when running at these higher compressions and you're not getting the full benefit when cruising at high speed and low revs?
All the best,
Andrew.
