I’m talking about your comments that gas and diesel used to be pure, made from only a few components. They never were. The big change over the last several years in gas has been adding ethanol. It improves octane, but decreases energy content.
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I didn’t say that. I opined that it was never pure. They start with crude; purification costs; the cheapest product is the least-pure that will do the job. I responded to @SteveCBT 's comment that it used to be something different, specifically with longer alkanes.
Then I have no idea what you meant when you said this.
I’m still waiting for the OP to return, in order to answer my question regarding whether he/she is attempting to use high-octane gas to compensate for an engine that is poorly maintained and/or in need of repair.
I fear the OP has been so confused by the replies they have committed themselves to a mental institution.
I believe it was meant in a facetious way. Diesel has an extremely low octane rating. Diesel has a cetane rating. Cetane is another name for hexadecane but a mixture of n-hexadecane and a branched isomer of hexadecane is used as a yardstick for diesel fuel’s ignition qualities.
A high cetane number = a low octane number. In a diesel engine, you WANT the fuel to burn the very moment it is injected into the cylinder. Diesel knock is caused by a delay in fuel ignition allowing a large amount of it to build up and then go bang. If the fuel ignites as soon as it comes out of the injector, there is no knock.
In a spark ignition engine, you start with a cylinder full of fuel and air and you want the fuel to wait for the spark to burn and when ignited, you want the fuel to wait for the flame front to arrive before burning.
Chemicals such as amyl nitrate are used to boost diesel’s cetane numbers, do not add this chemical to gasoline unless you want to convert premium gas into regular.
Also, do not mix small amounts of diesel with gasoline unless you really want to convert premium gas into regular.