HERE ON THE BIG ISLAND: Ethanol-Free Gas is Best for Small Engines

By Kelly Moran


Ethanol is ethyl alcohol – the kind you can drink. Diluting gasoline with this home-grown fuel, distilled mainly from corn, reduces America’s demand for imported oil.  The mixture has helped to moderate the rises in crude-oil prices, but it is widely criticized, from left and right both, as a subsidy to big agribusinesses, and as a diversion of corn that ought to be food for people and livestock.

Gasoline with ten-percent alcohol is called E10; with 15% it’s E15.  Burning alcohol yields less energy than burning gasoline: it takes 1.5 gallons of alcohol to equal the propulsive power of one gallon of gas.  In today’s automobiles – those built after 2000, anyway – that doesn’t matter.  Hundreds of times a second, the computer in the engine senses the percentage, and makes the optimum mix of fuel, air, and ignition timing, no matter what the fuel.  But small gas engines, like those of lawn-tractors, and particularly the even smaller gas engines of lawnmowers, chain-saws and weed-eaters, don’t have computers.  They have old-fashioned carburetors, which can’t make adjustments for the difference between gas and alcohol.  So they simply don’t perform as well burning E10 or E15 as they do burning pure gasoline.

Ethanol-Free Gas - Bayfront Chevron
This pump at the Bayfront Chevron calls its ethanol-free fuel “100% Gasoline,” but notes that it’s “not a Chevron product.”

With ethanol in the gas, though, there’s an even bigger problem for small engines than mechanical inefficiency.  If you have any landscaping to do at home, here, you probably have some small-engine tools.  But you probably don’t mow your lawn or whack your weeds as often as you drive your car.  So in a typical small engine, the fuel can hang around in its tank for a while, unused.  After a few weeks or a month, the alcohol separates from the gasoline; it starts dissolving things made of fiberglass (like the tank itself!), and corroding a few metal components.  And when those residues get into the fuel line and carburetor, they gum up the works.  Small-engine repairmen get business from this, but they are not necessarily happy about it.  They tend to have great respect for these well-engineered, highly efficient and reliable machines, and they hate to see them fail for fully preventable reasons.

The best “ounce of prevention” is ethanol-free gas.  Some automotive-supply stores sell it in small cans, by the pint or the quart.  But it’s cheaper to buy it and pump it yourself, by the gallon, and you can do that easily at a couple of gas-stations here on the Big Island.  For a long time, the only outlet was the Aloha station in Mountain View, on Hwy 11 between the 14- and 15-mileposts.  Recently, though, Hilo’s Bayfront Chevron, on Kamehameha Ave. at Pauahi St., has begun selling it too.

Chevron on Kam Ave
The Chevron station on Kam Ave. in Hilo has begun selling ethanol-free gasoline. Is this a sign of things to come? As more people become aware of the problems that ethanol causes in small engines, will more stations start to offer gas without the added alcohol?

Ethanol-free gas does cost a bit more than Regular E10 (about the same as Premium E10).  But a gas engine without alcohol is a cleaner-running gas engine.  Use it in your mower, chainsaw and weed-whacker, and you can take comfort in knowing that those tools will be giving you a big “Mahalo,” and working a lot longer for you.

One Reply to “HERE ON THE BIG ISLAND: Ethanol-Free Gas is Best for Small Engines”

  1. hi thank you !!…..for the education and the place i can go and buy this gas so hopefully i wont be taking the carburetor apart on the two small atv’s that little boys ride….doug

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