Perhaps I can rephrase it this way.
Higher Octane fuel is a more controlled burn, and you are correct it burns longer, therefore slower, therefore providing a longer power stroke, therefore able to have a more advanced spark.
Its tricky, as fuel injection controls the burn time.
the essence is this:
The ECU is tuned to burn 91 Octane, more or less can be adjusted for, but the extremes can cause problems. Many other factors effect the burn, thats why some can use 89 Octain without knocking, where some have to run higher to avoid knocking.
My appologies for my mistake.
You can spank me when you see me...
