Idaho Liberty posting categories

octane (what’zit’fo?) and ethanol

I stuffed a third-hand 912 flat-track-racer engine into my ’56 Porsche Speedster. It went like stink, but the high compression racing pistons required 50% aviation gas and 50% gas-station leaded premium … yes this was a while ago … during the existence of leaded premium.

I ran that exhilarating combination joyfully for a while, but I eventually tired of trips to the airport for 50% avgas fillups of my 30mpg daily driver, so I de-tuned the frisky filly.

High octane for non-engineers:

Higher octane reduces the volatility of the fuel so it does not ignite from the compression of the air-fuel mixture before the spark plugs order such ignition at the optimal moment of crankshaft rotation and piston positions. Higher air-fuel compression in engine designs force increased octane – while returning higher horsepower (mostly in highly-stressed racing engines) and more power per gallon.

If your engine requires a certain octane to avoid pre-ignition (aka pinging, also known to burn pistons and valves), exactly that octane is what you should be running. Octane too low damages the works. Octane too high reduces the engine’s punch as it does not burn as completely, quickly, or as efficiently as the correct octane.

Ethanol is a complete scam that the vindictive poopheads in charge are foisting on us. It has less power per gallon, requires LOTS of diesel, electricity and petro-fertilizer to produce, has short shelf-life, and screws up older non-alcohol-compatible engines. Government mandates and subsidies are the ONLY reasons it is on the market. Consumer demand is non-existent … as are consumer, human, or natural benefits.

Obscure side-note: Some may note that ultra-high-performance drag-racer engines use alcohol based fuel. That is because they are scientifically replacing the multitude of air molecules with the oxygenate contained in alcohol fuel. You cannot afford that level of engineering, or the requisite engine rebuilds after each day of quarter mile trips.

I avoid ethanol combinations on principle and also because its lower efficiency means you are paying more per gallon to propel your machine for the same distance.

At some level of higher mathematics/accounting you can figure out what the lower energy of ethanol costs to transport a given vehicle/passenger combination a certain distance compared to real gasoline against their relative costs, but that involves the widely dreaded algebra (aka: old math). If you wanna go down that rabbit-hole, don’t forget to include the taxpayer-costs of the subsidies and mandates.

In Montana the premium-grade fuel is non-ethanol. Little gasoline-powered tools require and specify this. I use that in conjunction with Sta-Bil in all my gasoline powered tools and gas cans for same.

It also goes into my vehicles, or 50/50 just cuz … no math, just stubbornness … tempered with personal fiscal limitations … and recognition that the efficiency improvement means little, no, or negative additional out-of-pocket cost for the upgrade.

… Voting with my dollars for real gasoline.


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Thank you, Ted Dunlap