slapnpop
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This is 100% correct.Octane rating is simply based on the fuel's knock tendancy (also called pre-ignition or pressure induced self-ignition).Knock tendancy is based on free radicals present in the fuel prior to ignition.
Octane is not a measure of power or energy but a measure of burn. Higher octanes can burn slower but may not.
Octane actually makes the fuel harder to ignite, hence it's use in very high performance engines. These engines make their power from the compression, not the octane in the fuel. An engine's power output is a funtion of the pressure created in the combustion chamber above the piston. The more compression, the higher the pressure at the moment of ignition and the more "push" down on the piston.
A fuel that does not knock (89 octane for the FJR) will produce the same power as higher octanes.
If your FJR knocks with 89, go up to 91. Other than that, it matters not. Use the lowest octane that does not knock.
Racing Gasoline and Alcohol (Methanol or Ethanol) is different and is really only needed when detonation problems are evident. Their energies are not really different from gas. 10% ethanol in pump gas is fine.
One addition,
Standard vehicles engines can preform better with higher octane gas, but the ignition timing must be advanced as well. Some engines have a "knock sensor" that helps the computer control the ignition timing, to keep it just before the point of knocking. This kind of system can adjust to the grade of fuel on it's own, if there is any benefit to be had. The FJR does not have a knock sensor, and does not make adjustments for the grade of fuel.