True stardog but when you want to have higher performance you will run the risk of pre detonation and as you mentioned yourself high octane fuel reduces this risk. So when an manufacturer knows that the available octane is low or the fuel is of poor quality (the one has nothing to do with the other of course) The reduce the risk of pre detonation. This can be done in millions of ways (for instance alter the detonation period, change headgasket or verry serious other pistons etc.


The ivtec is a very high tech engine with different modes for the cams and even difference in the time between the egnition of both sparkplugs in each cilinder.

Altering the egnition timing a bit is a small job.

Oh and don't rule out the perfomance levels at different altitudes. I live fifteen meters below sealevel. This really makes a difference compared to someone who lives at 1.000 meters above. This has to o with oxygen saturation in the air.

Pardon my spelling i've i make any mistakes.