About engines in general

4.1.1 The engine is the heart of your car

Engine is the heart of your car. It is thanks to it that you can move quickly or slowly, comfortably or not, but most importantly, without applying your own physical efforts. Fuel burns in the engine, creating traction, which is then transmitted to the wheels via the transmission. 

Engines can operate by burning a variety of fuels. In case if this fuel is gasoline, then the engines are called, respectively, gasoline. In order for gasoline to burn, it is ignited using spark plugs. Diesel engines use diesel fuel (often referred to as "heavy fuel") for its operation. It is ignited not by the spark plug, but by the air heated by compression.

4.1.2 Diesel engines

Initially, when diesel engines first appeared, they were slow in operation and ineffective compared to gasoline ones. But they became widespread in trucks, because they were cheaper during maintenance and operation. But progress does not stand still, and at the end of the 20th - beginning of the 21st centuries, cars with a diesel “circulatory system” became very popular due to the fact that diesel-powered engines approached gasoline ones in terms of their power characteristics. And in terms of engine torque and economy, they significantly surpassed the gasoline versions.

4.1.3 Gas motors

In pursuit of low cost and environmental friendliness, fuel systems powered by gas (compressed or liquefied) began to be installed on cars with gasoline engines. According to the principle of operation, no different from gasoline engines, gas motors really became an outlet for commercial vehicles, since they allowed to significantly reduce fuel costs. But from an environmental point of view, everything remained in question.

4.1.4 Hydrogen as an alternative fuel

Interesting 
For more than twenty years, various companies have been inventing developments in the field of using hydrogen as an alternative fuel. Therefore, active searches are now being carried out for the scheme and design, under which it will be possible to safely transport this gas by car.

4.1.5 Alternative propulsion systems

In general, taking into account the current environmental situation in the world, all automakers are investing huge financial resources in obtaining traction on the driving wheels, not by burning something in the cylinders of the internal combustion engine, but through alternative powertrains. So, for example, more and more often electric cars started appearing on the roads laid across all the continents. 

Electric motor powered by rechargeable batteries plays the role of heart in these cars. Everything would be fine, because it seems that there is no harmful exhaust, but rechargeable batteries are ineffective, capricious (capacity depends on the ambient temperature), explosive and very expensive. Therefore, most of the electric vehicles in operation at the moment are not sold, but leased on a long-term basis.

4.1.6 Hybrid propulsion systems

Still trying to find a way out of this situation, the designers decided to compromise: if the polluting effect cannot be completely ruled out, then at least one can try to minimize it. This is how cars with hybrid powertrains appeared. They are hybrid, because the creation of thrust is "engaged" in the internal combustion engine paired with an electric motor. We will consider the connection and interaction diagrams of both engines below. It is worth mentioning here that thanks to hybrid technologies, it was possible to significantly reduce emissions of harmful pollutants into the atmosphere. The benefits of purchasing a hybrid car are very conditional: despite the fact that the fuel consumption is really reduced in comparison with the fuel consumption of cars with one engine, the final cost and the cost of further maintenance of such cars negate all the advantages of the described scheme.