An engine is to a car what a heart is to a person. When people buy a car, in order to know more about the engine parameters of the target model, they will consult various materials. However, the performance indexes related to the engine are quite numerous and complicated. After all, not every consumer graduated from an automobile-related major. So, is there really no way to read these complicated parameters quickly? Wait a minute, after reading this article, maybe you can become an old driver, and all kinds of technical parameters are under control.
Rolls-Royce's 6.75L displacement engine.
Displacement can be said to be one of the most talked about and most important engine parameters. Generally speaking, in the respective categories of naturally aspirated engines and supercharged engines, the displacement is directly proportional to the power, and the displacement is also directly proportional to the fuel consumption and carbon emissions (simultaneously). Automobile engines usually have multiple cylinders, and we often say that the displacement is the sum of the displacement of all cylinders. It is worth mentioning that the engine displacement is usually not an integer, but it is usually obtained by rounding. For example, for a 2.0L naturally aspirated engine, the actual displacement may only be between 1980- 1999ml.
There are three main types of engine air intake: naturally aspirated, turbocharged and supercharged.
1.5L naturally aspirated engine on Volkswagen LaVida.
Natural inhalation is to use the negative pressure when the cylinder is running to inhale the outside air, similar to our breathing. To put it simply, an engine does as much work as it does in air. The advantages are naturally stable power output, longer service life and lower maintenance cost. If you choose an entry-level car with low power requirements, then naturally inhaling is definitely the best choice. (Of course, the charm of large-displacement self-priming is incomparable to small-displacement turbocharged engines. )
2.0T turbocharged engine on Volkswagen Tiguan L.
Turbocharging and mechanical supercharging can improve the intake efficiency in various ways, which can make the engine with the same displacement output stronger power performance. Turbocharged engine can be simply regarded as adding an air compressor, which pushes the exhaust gas of the engine to the turbine, and the turbine drives the impeller, which can compress more air into the cylinder, and the engine efficiency is naturally higher. The advantage of turbocharging is naturally high power efficiency, and now it has been basically applied to various models. However, turbocharged engines usually have different degrees of turbo lag. Choose a turbocharged engine model, try to choose a model with low turbine intervention speed, and the daily use experience will be better.
3.0L supercharged engine on Land Rover Range Rover Star Pulse.
The supercharger is usually connected to the pulley of the engine crankshaft with a belt. The rotation of the crankshaft drives the blades inside the supercharger to rotate, and the rotating blades send the generated pressurized air into the intake manifold. The advantage of this method is that the supercharging effect is not delayed, and it can reach the supercharging effect in the whole speed range, but it will produce greater power loss at high engine speed, so mechanical supercharging usually appears in large displacement engines.
BMW's inline six-cylinder engine is also a classic.
There are 3, 4, 5, 6, 8, 10 and 12 cylinders commonly used in automobiles (16 cylinders are also used in some models), among which 3, 4 and 6 cylinders are mostly used for family cars. As mentioned above, the displacement is often said to be the sum of the displacements of all cylinders, so when the displacement of a single cylinder is fixed, the more cylinders, the greater the displacement of the vehicle and the more advanced the vehicle. Generally speaking, the more cylinders an engine has, the less vibration it will generate during operation. However, due to the improvement of manufacturing technology and the addition of various vibration reduction technologies, even the three-cylinder engine can achieve excellent vibration reduction effect.
The maximum engine power of continental GT speedometer 388kW is 340 km/h..
Maximum power refers to the maximum power output that the engine can achieve. The maximum power is mainly related to the vehicle speed. The reason is also very simple. One air conditioner may only be able to cool a room of 10 square meter at most, while two air conditioners can cool a room of more than 20 square meters. Engine power will generally increase with the increase of engine speed. When it reaches a certain speed, the power will decrease, and that pole is the maximum power of the engine.
The maximum torque refers to the average torque output by the crankshaft when the engine is running. Simply put, it is related to the "strength" of the engine output. The greater the maximum torque of the engine, the better the climbing performance and acceleration performance of the car. Therefore, in fact, the maximum torque is more related to the real car. If you choose a car and pay more attention to the acceleration performance of the vehicle, you can know a thing or two by comparing their respective maximum torques.
As we all know, the engine does work by burning the mixture, so the way of mixing fuel with air is called the fuel supply way of the engine. Fuel supply mode is also called fuel injection mode, which is mainly divided into manifold injection (EFI), in-cylinder direct injection and mixed injection.
Manifold injection is also called EFI. The engine can calculate the air intake of the cylinder through the air pressure sensor or air flow sensor installed in the intake pipe, and the obtained data is transmitted to the engine electronic control unit (ECU), and then the ECU controls the solenoid valve to inject an appropriate amount of fuel after calculation. The advantage is also very simple, that is, use as much oil as you need, which has more advantages in fuel saving and emission.
Schematic diagram of in-cylinder direct injection
In-cylinder direct injection, as the name implies, is to inject engine oil directly into the combustion chamber, which can make the fuel atomization effect better, the combustion more complete and the power performance naturally better.
Toyota D4-S Double Injection Design
Mixed injection is simply the combination of the above two injection methods, which can not only have the advantages of on-demand manifold injection, but also increase the combustion efficiency in time, but the cost is naturally higher than the above two methods. However, it should be noted that the mixed injection settings of different car companies are not the same, and the "cooperation mode" of two injections will directly affect the dynamic performance of the engine.