The engine
Manufacturers tend to adhere to the new industry standards and use a four-stroke engine. The two-stroke engine, highly polluting and fuel-inefficient, is an endangered species. What's more, the four-stroke engine produces more torque and offers a better power/displacement ratio. The trend towards fuel injection seems to be firmly in place. On many models, this system features a catalytic converter, which is the best way to reduce emissions. It's cheaper to drive a four-stroke scooter. A four-stroke engine's useful life is much longer, and it eliminates the need for injection oil, which is very bad for the environment and quite inconvenient, as it tends to block the exhaust ports as well as the exhaust itself. In the end, the engine wears out much faster.

The four-stroke engine's maintenance requirements are cheaper than those of its two-stroke counterpart. Changing the oil or replacing the filter on a scooter is relatively the same as on a car or motorcycle. Some types of engine require a valve adjustment, while some use a hydraulic valve system that doesn't need adjusting, which might be an advantage for those interested in keeping maintenance costs to a minimum.

Honda Ruckus

The fuel system
Carburetor use is generalized; however, it will be replaced over time by fuel injection, which is cheaper but doesn't offer the best performance or entirely meet the new anti-pollution standards.

It needs to be adjusted and is rather expensive to maintain, and precautions must be taken when planning a lengthy storage period. However, the fuel injection system is more efficient and economical and responds better to temperature changes. On high ground, its sensors detect changes in atmospheric pressure and temperature and automatically calibrate themselves according to the different conditions.

What's more, some manufacturers support this technology with an exhaust system equipped with a catalytic converter and oxygen sensors that analyze the exhaust gasses directly at engine level. This system controls the emission of toxic exhaust gasses. A computer handles the data provided by the sensors, converts the signals and adjusts the amount of air/fuel mixture let in by the intake valve.

Though it sounds simple, it isn't. Other factors come into play: sensors, switches and controls complete the system. The computer even takes your passenger into account, and the engine will sense the increased weight. A request for extra torque will increase fuel consumption. The computer's sensors will enable it to react and adjust the injection of fuel accordingly.

Some high-tech scooter models feature a dash board that displays fuel consumption, the amount of fuel remaining the tank and the distance you can travel according to your speed.