This implies xylol is an alcohol. It is not. It is another name for xylene. (FWIW, toluol is another name for toluene.) Xylene actually has about 10% more energy than gasoline on a volume basis.
Xylene is di-methyl benzene, closely related to toluene which is methyl benzene. It’s one hell of an aggressive solvent as well as a fuel. It’ll even remove some paints.
@FoDaddy. Manufacturers are working on these systems again. There are significant potential advantages in cooling the hot charge coming out of a turbo- or supercharger with something. Methanol is good at this. It would have to be refilled regularly, but that's easy enough. We'll see. It has been researched for years.
I think this was done in some WWII fighter planes for peak power.
Indeed it was, There were some variants of the FW-190 and Me-109 that had it as well as some P-47, and F4U Corsair variants.
93 octane gets better gas mpg. I ran a newspaper route for almost 20 years on a 1980 and 1982 Toyota truck and I got better mpg on 93 octane and I tried 87 and 89. With 93 octane I didnt need to use any additives and my plugs and tail pipes stayed cleaner. But keep using 87 and learn the hard way.
For the same price, I’d use 93. Somengines have slightly more horsepower withe higher octane.
Never worried me using 87.
The higher the octane, the higher the resistance to burn. So all other factors being equal why would 93 octane burn cleaner than 87 octane?
Now, if that Toyota truck was old and had carbon buildup on the pistons, it might have been happier on higher octane to avoid predetonation. But from the factory I don’t believe any USA-available Toyotas in the early 80’s required 93 octane.
I ran a tank of 93 in my motorcycle even though the recommended octane was 87, because the station was out of regular. I actually got slightly lower gas mileage on that tank of gas.
If your plugs are fouling and you have a lot of exhaust deposits, you’ve got other problems.