Octane Rating for Gas

Sure, what grade school level do you want?

How about grade 7.

knock-resistant

Here you go:

Octane rating is a measure of a fuel's ability to resist knocking when run in an engine. An octane rating scale has been established for easy reference. Heptane, a fuel with very poor knock resistance, is rated a zero. Isooctane, a fuel with very good knock resistance, is rated a 100. A test using a special, standardized engine is used to determine the knock resistance of the given fuel. To establish the octane rating of the fuel, various blends of heptane and isooctane are run until it matches the knocking behavior of the gasoline being tested. For example, if the fuel's resistance to knocking is found to be equal to a blend of 30% heptane and

Thanks.

Is that RON or MON, current method for determining the octane as listed on the pump is (R+N)/2. My statement although oversimplified is correct. Knock is the result of fuel burning too fast, i.e. hot, and reaching full combustion before the piston passes TDC. The increased heat that results from higher compression engines demands a slower burning, i.e. colder, fuel to offset this and to insure a more even burn.

Motor Octane Number. The word "engine" gives it away.

(Research Octane Number + Motor Octane Number)/2 = Road Octane Number, or what's on the pump.

Sorry for the misinterpretation. I didn't realize hot and cold were synonymous with fast and slow, respectively. Since thermodynamics is not the same as kinetics, and vice versa, it's an honest mistake.