Let me speak with a little bit of authority on this. I design control systems for oil an gas refining platforms for a living, so I can tell you with confidence that you do not need to run premium fuel in an engine unless it is dictated by a high compression ratio or a radically advanced timing map. Doing so will not change the performance characteristics of the stock engine in any meaningful way.
The only things the octane number represents is the resistance to spontaneous detonation of the fuel mixture and the volatility of the fuel. As a gas is compressed, its temperature rises. A high compression motor increases the pressure significantly more than a lower compression motor, which causes the mixture to be raised to a higher temperature. All combustible mixtures will spontaneously combust (i.e. without a spark) at some temperature. Lower octane fuel has a lower temperature of spontaneous combustion than does high octane fuel.
So, if you have a high compression motor, it is possible to spontaneously detonate a mixture of 87 fuel before the spark plug fires. This detonation causes the "ping" sound that you may hear.
A quick note on ignition timing. One other property of higher octane fuel is that it burns more slowly than lower octane fuel, because it is not as volatile. This means that if you are going to advance your timing significantly from stock, a higher octane fuel may also be indicated to prevent the combustion cycle from ending before the piston reaches bottom. If this occurs, the combustion cycle ends and the temperature starts to fall, causing the pressure to fall, but the piston is still increasing the volume, so what happens is that you lose any pressure at all on the piston, and you do not get a complete power stroke.
But, the other note on timing is that regardless of when you detonate the fuel, the amount of energy is the same, so whether you spread your combustion cycle over a longer time is really irrelevant to the power output of the engine. If you plan to run extremely high RPM, it may be necessary to advance timing so the fuel has enough time to burn completely before the piston reaches bottom, but I can't imagine any other reason to advance the timing significantly.
Finally, a quick note on "octane boosters." All these things do is lower the volatility of the fuel by introducing ethanol. Ethanol has a very high equivalent octane number and, when mixed with fuel, will ever-so-slightly increase the detonation temperature. Usually, a 12oz bottle of "octane booster" will do more or less nothing for you in terms of ignition temp, and will actually decrease the amount of energy taken into the cylinder on the intake stroke, because ethanol has a much lower volume energy density than gasoline.
Hope this is helpful
