PWC Compliance with the U.S. Environmental Protection Agency’s Clean Air Act rules
In compliance with the U.S. Environmental Protection Agency’s Clean Air Act rules, the marine manufacturing industry is addressing many of the concerns surrounding 2-stroke engines by developing cleaner, more efficient models and by improving the performance of traditional engine components.
For example, the industry is redesigning piston-top deflectors (to reduce raw fuel throughput) and enhancing exhaust manifolds to decrease the release of airborne hydrocarbons and carbon monoxide. The industry is also using technologies such as direct fuel injection (DFI) systems and catalytic converters to reduce harmful hydrocarbon emissions and improve fuel economy (PWIA 2000).
Despite these improvements, DFI-2-stroke engines still have higher emissions levels than 4-stroke engines (Bluewater Network 1998; Gabele and Pyle 2000). Therefore, certain manufacturers are now producing 4-stroke engines for a wider variety of vessels, including PWC and high-performance motorboats. (See Box 1 for more information about 2-stroke and 4-stroke engines.)
