Octane only applies to the ability of the fuel to resists premature detonation due to compression and heat. As long as the fuel does not cause your engine to ping (premature detonation) you’re OK. Specific gravity of fuel can make a difference to milage. For instance JP5 is the standard Navy jet fuel. It weighs a bit more than other jet fuel and has more BTU’s available per gallon. Because of that an aircraft burning JP5 can go a bit farther than one using standard commercial fuel. Similarly, here in Iowa everyone seems to love ethanol blended gas. But because ethanol has fewer BTU’s per gallon than gas, fuel mileage is lower. Pure gas may have a lower octane but it will get more miles per gallon.
We all like to think of ourselves as rugged individualists. But when push comes to shove most of us are sheep who do what we are told. Worst of all, a lot of us become unpaid agents of whoever is controlling the agenda by enforcing the current dogma on the few rugged individualists who actually exist.
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