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To meet recently proposed exhaust emission standards, the Environmental Protection Agency (EPA) says manufacturers for the first time will use catalytic converters in many types of lawn equipment, garden equipment and small watercraft.

While using catalytic converters is one way to meet exhaust emission standards for nonroad spark-ignition (SI) engines rated below 25 horsepower, it is not the only way. Instead of using exhaust catalysts, Kohler will use another form of after-treatment, its own unique Exhaust Induction System for an interim solution. Subaru Robin's solution includes an efficient combustion chamber and redesigned piston rings to reduce oil consumption. Kohler's final solution also will include an efficient combustion chamber and redesigned piston rings.

Current EPA regulations for small engines focus on reducing hydrocarbons, which can be done by controlling engine oil consumption through tight engine manufacturing standards, says Richard Koehl, Kohler director of marketing and quality.

"The proposed EPA guidelines are much more stringent than the old ones," Koehl says. "You must have some form of after treatment or better manufacturing technology to achieve the levels they're looking for."

Specifically, the proposed standards include hydrocarbon and nitrogen oxides exhaust emission standards of 10 g/kW-hr for Class I engines starting in the 2012 model year and 8 g/kW-hr for Class II engines starting in the 2011 model year. EPA is not proposing new exhaust emission standards for hand-held equipment. For spark-ignition engines used in marine generators, EPA is proposing a more stringent Phase 3 CO emission standard of 5 g/kW-hr, and this would apply equally to all engine sizes subject to the Small SI (spark-ignition) standards.