I recently received a question on octane ratings similar to the questions I typically receive. The reader wanted to know what the rich and lean rating would be for 100, 110, 112, 114 and 118 octane racing gasolines. And what would be the R+M/2 of 80/87, 100/130, 100LL, and 115/145 avgas?
The problem here is that the octane rating of a fuel is not a physical property of a fuel, it is a performance property. It is like someone asking “What is the horsepower rating on a Lycoming 540 engine?” [Read more…]