Please tell me you're joking. This is from wikipedia:
"The octane rating is a measure of the resistance of petrol and other fuels to autoignition in spark-ignition internal combustion engines."
Spark-ignition engines are knock limited which means they will detonate (or pre-ignite) before the spark plug fires. This causes damaging pressure waves that will eventually destroy an engine. Using a higher octace rating fuel moves the knock threshhold and allows the engine to operate with a more advanced spark. When you use lower octane rating fuel in an engine tuned to use premium, the computer has to pull timing which reduces power. If the car was not designed to use premium, the spark tables are already tuned for lower octane fuel, meaning the spark advance has already been pulled out.
If you think only Ferrari's do this, well then, keep putting the cheap gas in your car and be happy.
