When 58 million weekend warriors fire up gas-powered lawn mowers, trimmers and edgers this summer, they will produce more than tidy lawns. Those small engines will emit one-tenth of the total hydrocarbon emissions produced annually in the United States.

But homeowners can do their part to reduce air pollutants, by using fuels with a 10 percent ethanol mix. Use of ethanol can reduce greenhouse gas emissions by 35 percent to 46 percent according to the Ethanol Promotion and Information Council.

The typical walk-behind lawn mower exhales more than 1 pound of emissions in 25 hours of operation each year, according to the Outdoor Power Equipment Institute. That compares to 10 pounds of smog-forming pollutants a new automobile creates in the same period.

Ethanol contains oxygen and burns cleaner than non-ethanol unleaded gasoline. Ethanol is produced by virtually any source of bio-waste cellulose material such as corn stalks and wood chips.

The ethanol industry is trying to debunk the notion that ethanol fuels contribute to engine wear and tear. Tom Slunecka of EPIC says, “At a 10 percent blend, ethanol-enriched fuel has been shown to decrease engine wear and increase engine longevity.”

A study published in the journal Environmental Science and Technology reports “the average consumer would not experience equipment failures which result in loss of use or unusual repairs.” Researchers ran lawn mowers powered by ethanol more than 1,300 hours, equivalent to three to five years of use. Engine inspections revealed “the gasoline/ethanol blend provided better lubricity than the control fuel.”

Engine manufacturers have taken notice of ethanol. The Web site of Briggs and Stratton, a primary maker of small engines used in yard equipment, approves ethanol but tells visitors the company “recommends that no more than 10 percent ethanol be used in our engines.” The firm recommends draining fuel tanks after the mowing season as ethanol has a tendency to attract moisture.

Ethanol can also power two-cycle engines that require a 50-to-1 mix of gas and oil. Most lawn mowers are four-stroke engines that do not use the gas-oil mixture.

Regular small-engine maintenance such as new spark plugs and air filters also contribute to reduction of air pollutants.

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