Car knowledge, car owners must see, don't miss it.

Car knowledge, car owners must see, don't miss it.

1, compression ratio: Some people don't know how much gasoline to add to their cars, and each car has its own suitable model, which is related to the compression ratio of the vehicles. Compression ratio refers to the ratio of the total cylinder volume to the combustion chamber volume, indicating the degree to which the gas in the cylinder is compressed when the piston moves from the bottom dead center to the top dead center. Compression ratio is an important technical parameter to measure the performance index of automobile engine. Generally speaking, the more compression, the higher the pressure and temperature of the mixture, and then more power will burst out, burning faster, more power, higher fuel utilization and better economy. Too high compression ratio can not only improve the combustion condition, but also cause deflagration and affect the performance of the engine. At this time, you should use No.95 gasoline, which has better antiknock performance. If your car has a low compression ratio, there is no need to use high-grade gasoline.

2. Power: Power refers to the work done by an object in unit time. Generally speaking, the engine power and engine speed are reliable. The faster the revolution, the higher the power and the higher the vehicle speed, but after reaching a certain speed, the power will drop. Maximum power is often used to describe the dynamic performance of a car. The maximum power is generally expressed in horsepower (PS) or kilowatt (kW), and 1 horsepower is equal to 0.735 kW.

3. Displacement: The working volume of the cylinder is the displacement, that is, the volume of gas swept by the piston from the top dead center to the bottom dead center, also known as the horizontal bar displacement, which is generally expressed in milliliters. The displacement of the engine is one of the most important structural parameters, which can directly represent the size of the engine.

4. multipoint injection: Generally, the EFI device of an engine in an automobile consists of an injection circuit, a sensor group and an electronic control unit. If the injector is installed on the intake pipe of each cylinder, that is, gasoline is injected into the cylinder from multiple places (at least one injection point per cylinder), this is multi-point injection.

5. Torque: Torque is the force that makes an object rotate. The torque of the engine refers to the torque output by the engine from the crankshaft end. At a certain power, the engine speed is inversely proportional to it. The faster the revolution, the smaller the torque. When starting, the greater the torque, the faster the starting speed.

Compared with the car with the same engine, the greater the torque output, the greater the bearing capacity, the better the acceleration performance, the stronger the climbing power, the less the gear shifting times, and the less the wear on the car. Especially when the car starts at zero speed, it shows the advantages of large torque and fast lifting speed. The torque of the engine is expressed in nm. Like power, the maximum output torque of the engine is generally indicated, and the speed is also indicated. The maximum torque generally appears in the middle and low speed range of the engine. As the engine speed increases, the torque will decrease.