Which machine creates the most air pollution per hour of operation: the typical car, or gasoline-powered lawn mower?

A single two-stroke engine such as those found in lawnmowers produces pollution equivalent to that of 30 to 50 four-stroke automobiles.

The EPA estimates that one hour of operation by a 70-horsepower two-stroke motor emits the same amount of hydrocarbon pollution as driving 5,000 miles in a modern automobile!

The two-stroke motor, found on 75 percent of all boats and personal watercraft (jet skis), generates 1.1 billion pounds of hydrocarbon emissions each year.

Every year, marine two-stroke motors spill 15 times more oil and fuel into waterways than did the Exxon Valdez.

Two-stroke engines are highly inefficient users of fuel: up to 40 percent of the fuel and oil goes out of the exhaust pipe unburned. This exhaust is packed with oxides of carbon, nitrogen, sulphur, hydrocarbons and fine dust - all toxic contributors to air pollution.

The 2-stroke engine emits significant amount of particulate matter (PM), un-burnt hydrocarbons (HC), Carbon Monoxide (CO) and Nitrogen Oxides (NOx).

It is estimated that particulate emissions from a single 2-stroke motorcycle is comparable to those from a diesel truck or bus.

The following machines typically use two-stroke engines:

Gasoline-powered landscaping equipment such as lawnmowers and trimmers

many outboard motors

chain saws

leaf blowers

some snowmobiles

smaller motorcycles