said:
The octane rating of gasoline essentially tells you how much the air-fuel mixture can be compressed before it will spontaneously ignite.
said:
So, octane does not enhance the explosion in the cylinder like most people think. What does octane do? It just prevents the air-fuel mixture from igniting before the spark plug does it. Firing the air-fuel mixture at the proper time gives you the maximum power your engine was designed to get
This is the key ---> Octane is a measure of the fuel to resist pre-detonation. That's the only relevant point in that article to this discussion and the article is absolutely miss-leading.
Pre-detonation can occur to ANY car when: too high cylinder compression, too high cylinder temperatures, too advanced timing or engine is experiencing too high a load. Modern cars (including non-performance cars) have several ways to deal with this, the most common is to reduce timing advance to make less power and cool down the engine. More advanced engines can also adjust cam timing, reduce fuel mixture, reduce throttle, increase cooling fans on the rad, etc.
Engines are pumps, the more fuel and air you can get into it, the more power it will make (all else being equal). Compared to ancient L-76s and L-79s which relied on STATIC compression and vacuum/mechanical advances to spark timing, many/most modern engines use variable cam timing, variable lift and changes in cam overlap that modifies actual compression ratio, increase fuel injector time, electronic spark timing and in some cases forced induction (supercharger, turbocharger). Several sensors are used to control all this; prevent detonation, prevent overheating, optimize fuel/oxygen ratio, maximize fuel economy and reduce emissions. Modern engines are incredibly sophisticated and are ideal example of a closed-loop control system. FYI: it was Canadian engineers that developed allot of this technology for the big name manufacturers.
By running higher octane fuel, the engine computer can use a more aggressive mapping that results in noticeably more horsepower and improved throttle response and contrary to most people's thinking, improved fuel economy (efficiency is the key). Octane is the enabler, which allows for increased fuel/air that makes the additional power. On a performance car the difference in factory programming can be 20-50 HP and with aftermarket ECM code 100+ horsepower.
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Using higher-octane gasoline than your engine is designed to utilize is only wasting your money.
^-- ONLY TRUE for engines that don't use the technologies I described above. For most non-performance engines, there is no benefit to running higher octane fuel, including for the "cleaning" benefits.
