The engine can be said to be the most important part of a car, and its layout has a major impact on the performance of the car. For cars, the layout of the engine can be simply divided into three types: front, middle and rear. At present, most models on the market use front engines, and mid-mounted and rear-mounted engines are only used in a few performance sports cars.

The front engine is before the front axle. The advantage of the front engine is that it simplifies the structure of the car's transmission and drive axle. Especially for the front-wheel drive models that currently occupy the absolute mainstream, the engine directly transmits the power to the front wheels, omitting the long drive shaft. The power transmission loss is reduced, and the complexity and failure rate of the power transmission mechanism are also greatly reduced.

Mid-mounted engine, that is, the engine is located between the front and rear axles of the vehicle, and generally the cockpit is located before or after the engine. It can be said that a mid-engined car must be rear-wheel drive or four-wheel drive.

When a car is turning, all parts of the car will move out of the corner due to inertia. The engine is the most massive part, so the force of the engine on the car body due to the inertia has a vital influence on the car's steering in the corner. The feature of the mid-engine engine is to place the engine with the greatest inertia in the center of the vehicle body, so that the weight distribution of the vehicle body can be close to an ideal balance. Generally speaking, only those super sports cars or sports cars that pay attention to driving pleasure use mid-engines.

Of course, the mid-mounted engine also has its shortcomings. Because of the mid-mounted engine, the cabin is narrow and cannot be arranged with more seats. In addition, because the drivers and passengers are too close to the engine, the noise is louder. However, people who only pursue car driving performance will not care about these anymore, and some people even prefer to hear the roar of the engine.
Generally speaking, the purest rear-mounted engine is to place the engine behind the rear axle. The most representative one is the bus, and there are only a handful of passenger cars with the rear-mounted engine. The most representative is the Porsche 911, and of course the smart It is also a rear engine.