V.P. C-11 vs. C-12

[James L Miller]

https://en.wikipedia.org/wiki/Octane_rating

Usually the short chain alkanes like methane and ethane have the higher octane ratings. And they usually are the ones that boil off first, so the old stale/flat gas has probably lost the good stuff and eventually you end up with paint thinner or varnish.

That chart I think is wrong on benzene. I've always heard it's off the chart and they couldn't get an engine to knock on it, so MON of 130 or so. I think that is the top number in the rating system.

All these ratings are performed on a single cylinder engine made by Waukesa. It probably doesn't look like anyone's racing engine. Perhaps closer to a farm tractor engine.

http://www.waukeshacfr.com/f1-f2/