We used to be allowed to burn our leaves here in the old days... Once in a while we would take the easy way out and throw some gas on the leaves to get them going....
When we threw 93 octane on them, it did not light right away, a slight pause and then poof!!!
When we threw 87 octane on the leaves, no pause ---> POOF!!!!
The lower octane is more flammable and burns easier...
Octane is the resistance of gas not to burn... The higher the octane, the harder it is to burn.... The lower octane, the easier it burns...
That's why high compression engines need high octane so they don't pre-ignite early from the higher cylinder pressure...