|
There is no octane in fuel, please READ my previous post. In my previous post, it tells how the "RESEARCH" octane number is established (by comparing the fuel to a mixture of isooctane which has an octane number of 100, and heptane, which is assigned an octane number of 0), then on Lycoming-8's post it explains how the MOTOR number is established, and the average of both of these numbers is how the "Octane" number posted on the pumps is derived.
By increasing the ratio of isooctane in a combination of isooctane and heptane, the "octane rating" of that mixture is higher than if the ratio of isooctane is lower, that's all part of the "research method", but they don't actually PUT the isooctane into the fuel, this is only the mixture used in comparison with gasoline.
They used to use tetraethyl lead to increase octane, now they have to use aromatics or some other stuff, it's all explained in the first link I put up if you care to read it.
Gilly
|