The term automobile is commonly used to refer to motor vehicles with four wheels. Cars usually have seating for a few passengers, but they can be converted into vans or trucks to carry more cargo.
The word automobile is defined as a “motor vehicle whose primary purpose is to transport people and/or cargo”. However, an automobile must also meet certain safety standards. Those are:
An automobile must be designed to be driven on a road or a road network. It must have a seat belt and a gear change mechanism. Generally, power is transmitted through a chain or shaft.
Automobiles are classified into three groups: commercial, sport and Economy. Commercial vehicles account for 56 percent of total sales. Sport and Economy vehicles typically use smaller engines, are less powerful, and have a lower price point.
Motorcycles are two-wheeled motor vehicles that use a single cylinder engine. They are designed to lean to the rear, which improves cornering ability. A motorcycle’s steering geometry is also important for cornering.
In the United States, the Environmental Protection Agency requires motorcycles to emit no more than five grams of hydrocarbons per km. This limit was reduced to 0.8 grams in 2010. In the European Union, new motorcycles were limited to 0.3 grams of hydrocarbons and nitric oxides in 2007.
In the United States, the Environmental Protection agency first regulated the emission of hydrocarbons from motorcycles in 1980. Motorcycles are required to wear a helmet. Some states require the motorcycle driver to wear a seat belt and to obey posted speed limits.