These vehicles typicall have four wheels, unladen mass not more than 350 kg, not including the mass of the batteries. Maximum design speed is not more than 45 km/h and maximum continuous rated power does not exceed 4 kW.

Heavy quadricycles have four wheels, unladen mass is not more than 400 kg or 550 kg for vehicles intended for carrying goods, not including the mass of batteries. The design payload not more than 200 kg (passenger) or 1000 kg (goods) and maximum net engine power does not exceed 15 kW.

With two classes of vehicles most modern transportation needs are met for individuals and small businesses.

Motorized Cycles are becoming common in many countries. In those countries they are the least expensive and most widespread forms of motorized transport. It is also a means of reducing the effects of urban congestion and pollution.While the reasons for people choosing to ride smaller vehicles like these are many and varied, those reasons are increasingly practical.

Motorized tricycles are a quick way to travel through traffic and conserve energy.

Styles vary depending on the task for which they are designed. As can be seen from the streamlined appearance of new three wheelers there is aerodynamic technology included in the design. Modern fairings and enclosed compartments on vehicles dramatically improve a rider's comfort and attention on long rides by reducing the effect of the wind and rain on the body. Some even are designed as trucks or taxis. Others are multi passenger. Many are fitted with tilting wheels as in the picture above.

Almost all cycles are driven by conventional gasoline internal combustion engines. Some small scooter-type models use an electric motor and a very small number of diesel models exist. Liquid-cooled ones have a radiator giving them the potential for greater power and longer operating life. Air cooled engines are cheaper to purchase, less complex and lighter weight.

Only a few models are fitted with a reverse gear, usually just the larger ones. At one time, they all used spoke wheels built up from separate components, but one-piece wheels are more common now. Brakes can either be drum or disc based. Disc brakes being more common due to their superior stopping power, particularly in wet conditions.

>Above is a sedan used in Asia, Right is a Chinese delivery version. Pictured at the top is a Peugeot modern version.

This is a list of all the motorized tricycle and quadricyclecycle manufacturers. Historical and current vehicles included.
Names in bold type have web sites. The rest are Wikipedia articles.