Originally Posted by Neil

Something does not sound right. High octane fuel is typically used for high compression engines, and is required to prevent pre-detonation. It is actually less combustable (more stable) than lower octane. Does anyone know what the compression ratio is for the Accord v6?

For the HAH, the extra '10' HP and '10' lb ft. would contribute to better fuel effeciency at all speeds. Yes, it would be noticable when you put your right foot into it, but for normal driving it would show up in MPG.