Scooters/Motorcycles

Motorcycles and scooters fit into the small engines category, with the exception of a few larger motorcycles. The small size of these vehicles means they're much more fuel efficient for one person to drive compared to a car (65 miles per gallon for the average motorcycle vs. 25 miles per gallon for the average car). However, their small size also helps contribute to the amount of pollution they produce.

How do these vehicles produce pollution?
Like cars and trucks, motorcycles and scooters burn gasoline, a hydrocarbon-based fuel. The ideal combustion products of gasoline, IF the process is 100 percent efficient, are carbon dioxide (CO2) and water (H2O). However, combustion of these fuels in cars today is far from 100 percent efficient. So the combustion process also produces nitrogen oxides, particulate matter, carbon monoxide, and other pollutants.

Motorcycles are too small for most pollution control devices (i.e., catalytic converters) to be an economical, easily added part of their equipment, and riders are usually more concerned with performance than emissions. However, there are some motorcycles on the market that ARE designed with reduced emissions in mind.

How much pollution do they produce?
According to EPA, emissions non-road engines and highway motorcycles together account for about 11 percent of hydrocarbon (HC) emissions, 9 percent of carbon monoxide (CO) emissions, and 3 percent of oxides of nitrogen (NOx) emissions from mobile sources. Off-highway motorcycles alone emit more than 134,000 tons of hydrocarbons (HC), 181,000 tons of carbon monoxide (CO), and 1,000 tons of oxides of nitrogen (NOx) each year across the United States.

Are there laws regulating this pollution?
Not as many, or as stringent, as those regulating emissions from cars and trucks. In October 2001 the U.S. EPA proposed emissions standards for a variety of small engine vehicles, both on-road and off-road. You can read the proposal here: http://www.epa.gov/otaq/regs/nonroad/proposal/cleanrec.htm.

How could they be made to produce less pollution?
AT THE FACTORY
By using four-stroke engines instead of two-stroke engines, changing the air-fuel mixture, or using a technology such as advanced fuel injection or catalytic converters on some models to meet regulations.

AT HOME
Owners are responsible for maintaining their vehicle's efficiency once it leaves the dealership. Having the vehicle serviced regularly and performing simple maintenance tasks can all reduce the amount of pollution the vehicle produces. Because maintenance is such a huge component of motorcycle safety, most owners already take good care of their bikes.