What Is a Honda Tier 3 Motor?

CARB

• CARB has been collecting and collating information on emissions and air pollution since 1969. The statistics collected are intermittently compiled into pollutant emission inventories that form the backbone of the state air pollution control programs. The summarized findings are published by CARB annually.

Small Engines

• Along with monitoring pollution sources such as powerplants, refineries, consumer products and on-road vehicles, CARB also quantifies the emissions of off-road vehicles, including aircraft, ships and trains. The Environmental Protection Agency has determined that small internal combustion engines produce around 5 percent of the hydrocarbons that exist in the ground-level ozone formation -- the air that we breath. Since 1995, the EPA has regulated emissions from several classes of non-road engines at or below 25 horsepower.

CARB and EPA Regulations

• The EPA’s sub-25-horsepower controls were implemented in phases; as of February 2012, Phase 3 is in force, which took over from Phase 2 in 2007 and was entirely implemented by 2011. Within the Phase 3 mandates there are three tiers of emission standards; of these, Tier III is the strictest. In fact, CARB’s Phase 3, Tier III emissions controls are the most rigorous exhaust emissions regulations in the world.

Implications for Aftermarket Users

• Tier III limits the emissions of all internal combustion engines that could impact air quality. This includes engine-powered machinery such as fire pumps and chain saws. Manufacturers of such equipment that use aftermarket engines -- meaning they buy in complete engines, rather than build their own -- only have to show CARB-compliant emission certification issued to the engine manufacturer, rather than pay for testing themselves. This results in a considerable cost and time saving. This rule-of-thumb does not apply to extremely high-volume producers; for instance, pump-makers manufacturing more than 10,000 units a year must have additional certification.

Honda

• Honda manufactures approximately five million general-purpose engines every year; 70 percent are sold to other makers of power equipment. In this context, “general purpose” means non-road-going engines used in industrial, construction and agricultural applications, as well as home-use equipment such as generators, lawn mowers and other gardening machinery. For the 2012 model year, Honda has three series of commercial-use engines, two frame-mounted home-use series and one hand-held home-use series. All have passed CARB’s Tier III testing.