How clean is clean?
The effort to clean our air of pollutants is laudable, but at what cost and where does it end? In the case of engine emissions, the U.S. Environmental Protection Agency (EPA) has imposed stricter standards on both on- and off-road vehicle engines, hand-held-equipment engines and residential- and commercial-mower engines. The EPA has set up a multi-phased system to implement the emission standards for residential and commercial lawn equipment under 25 hp, which EPA contends contributes 7 percent of the ozone-forming hydrocarbon (HC) emissions. Phase I, effective with the 1997-model year, anticipates a 32-percent reduction in HC emissions and a 2-percent reduction in carbon monoxide (CO) emissions by the year 2020. Phase II, effective between 2001 and 2005, expects a further 40-percent reduction in HC emissions from Phase-I standards.
To meet Phase-II standards, engine manufacturers are emphasizing cleaner, more durable engine technology, such as overhead-valve engines with superior combustion-chamber and cylinder-head design. EPA expects engine manufacturers to shift their production completely to OHV or comparable technology as a result of these standards. Taking the next step to implement Phase-III standards is almost a given. In the case of hand-held-equipment engines, EPA insisted that a technology review and consideration of Phase-III standards be conducted in 2001 for more stringent standards to be implemented in 2007.
What does this mean in the grand scheme of air pollution? The Outdoor Power Equipment Institute (OPEI) says, "Not much." OPEI says, "Four-stroke gasoline- and diesel-powered engines contribute only 2.6 percent of the total volatile- organic-compound emissions. By contrast, all non-road engines account for 9.7 percent; highway emissions (automotive) account for 33.3 percent; and other sources (power plants, paints, solvents, waste disposal) account for 57 percent." Considering these points, this issue focuses on grounds-care equipment.
Are you in the market for a new mower or replacement engine? First, evaluate your needs and consider which type of cooling system--liquid- or air-cooled--works best for you. Factors such as cost, serviceability and longevity come into play. Larry Van Deusen, technical advisor for the College of Agriculture and Technology at the State University of New York, compares the characteristics of liquid- and air-cooled engines (page 14).
Most riding mowers today are equipped with air-cooled engines, but liquid-cooled engines and diesel are becoming more popular. Aside from engine types, many other features--zero-turn capability, hydrostatic drives, mowing-deck options and increased creature comforts--are making riding mowers far different from mowers of the past. Find out what mower manufacturers say about the latest innovations in riding-mower design (page 20).
Although today's riding mower is designed to improve productivity by cutting down on trimming requirements, it can't eliminate all of them (yet). That's where spin trimmers come into the picture. Learn about currently available trimmers and their efficient use in this issue's "What's New" department (page 72).
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