Octane

[matt at safearmy.com (matt)]

ok i pulled this form here
http://encyclopedia.laborlawtalk.com/octane_rating

It supports my argument that that the stock 8v is fine with 87

Octane rating

The most important characteristic of petrol is its Research Octane Number (RON) or octane rating, which is a measure of how resistant petrol is to premature detonation (knocking). It is measured relative to a mixture of isooctane (2,2,4-trimethylpentane) and n-heptane. So an 87-octane petrol has the same knock resistance as a mixture of 87% isooctane and 13% n-heptane.

There is another type of Octane, called "Motor Octane Number" (MON), which is a better measure of how the fuel behaves when under load. Its definition is also based on the mixture of isooctane and n-heptane that has the same performance. Depending on the composition of the fuel, the MON of a modern petrol will be about 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the 'headline' octane that would be shown on the pump is the RON: but in the United States and some other countries the headline number is in fact the average of the RON and the MON, sometimes called the "Road Octane Number" or RON. Because of the 10 point difference noted above this means that the octane in the United States will be about 5 points lower than the same fuel elsewhere: 87 octane fuel in the United States would be 92 in Europe.

It is possible for a fuel to have a RON greater than 100. This reflects the fact that isooctane is not the most knock-resistant substance available. Racing fuels, Avgas and LPG typically have octane ratings of 110 or significantly higher.