49-542.04. Off-road vehicle and engine standards A. The department may adopt rules for air pollution emission standards for off-road vehicles and engines marketed in the state beginning with the 1999 model year. B. The standards may include the following categories: 1. Heavy-duty diesel vehicles rated at 175-750 horsepower. 2. Small utility and lawn and garden equipment engines rated at less than twenty-five horsepower. 3. Recreational vehicles rated at less than twenty-five horsepower. 4. Specialty engines and go-carts rated at greater than twenty-five horsepower. 5. Off-road motorcycles and all terrain vehicles. C. In a county with a population of more than one million two hundred thousand persons, the department may adopt rules for air pollution emission standards for golf cart engines.
Arizona Legal Code