The has been some chatter now and then about it, and one night when I was sippin' Jack I decided to check it out for meself.
Since nobody is concerned about octane ratiing in thier coleman lanterns and camp stoves, it isn't controlled or published, but I did find a post about this from someone who had worked in a refinerey that sold base product to Coleman years ago...octane could be as low as 55, as high as 70, dependant on what exactly was in the stuff.
Coleman is actually pretty stringent about quality; they want a fairly narrow range of individual molecules and isomers for clean burning, and very very little ring-chain (benzene) ones...they burn smoky and most are carcinogenic. Cook with that? Benzene ring molecules are noted for high octane...Pure Toluene is around 115.
Coleman fuel also contains a (usually green) dye (I remember another brand as a kid that was blue) and a couple of compounds to retard polymerization and oxidation...Coleman fuel will "keep" longer than gas. Because Coleman fuel is mostly short, straight-chained monomers (think pentane, hexane, and maybe septane) with little branched-chained isomers, its heat of vaporization is low and the fire lights easy. This is cool if you're trying to milk a little more life out of a tired old warhorse. There's no need to worry about most other additives (phosporus or mettalic top end lubes are already IN two-stroke oils)
I tried it in a green weedeater that only has about 90lbs of compression: a performance increase, and it starts very well. Runs hot though...can feel it with the motor next to your hip. I also tried it in an old Techumseh ice auger: same story; easy starting at 10 below. I also put a little in a Briggs pushmower...flathead engines do not control detonation well, and you could hear it knocking and pinging when cutting heavy grass.
So I had a fun little experiment. But if I'd had to go to the hardwar store especially to get a gallon or two of the stuff I might have balked...its almost $9 a gallon in my little burg. IF long storage life was a concern, I'd look around for some of the other products like 40:fuel, or even some of the race-gas products. In a pinch you could take two gallons of Coleman, 1 gallon of Toluene from the paint store and have around 88 octane; mix a full-synth two stroke oil at 160:1 for 4-strokes, 40:1 for two (approximates the additive package in better commercial gas)
It would last 5 years, but cost $13/gallon. Plus, if you wanted to buy very much you'd have to register with the FBI.