The Difference Between a Three-Cylinder Engine and a Four-Cylinder Engine

by MOU YONG HONG on December 01, 2021

In recent years, car companies have paid more attention to environmental protection and have strengthened their environmental protection efforts. For 4-cylinder engines, simply reducing the displacement can no longer play a big role in reducing emissions. Therefore, various car companies have gradually Started the development of a three-cylinder engine.

The difference between a three-cylinder engine and a four-cylinder engine:

1. The three-cylinder engine has a simple structure, small size, lightweight, and easy layout. The four-cylinder engine has a relatively complicated structure and has one more cylinder. The three-cylinder engine has one less cylinder than the 4-cylinder engine in terms of structural design, and the corresponding cam There are also fewer shaft attachments.

2. The three-cylinder engine has less pumping loss. The three-cylinder engine has one less cylinder, theoretically, the resistance will be smaller, and the resistance loss caused by mechanical friction will be less than that of the four-cylinder engine. Fuel consumption will be slightly lower.

3. The low-speed torque output of the three-cylinder engine is large, but the high-speed torque is relatively small, and the power attenuation is relatively large. The cylinder diameter of the three-cylinder engine is small and the piston stroke is long. This design is beneficial to the low-speed torque of the engine. Therefore, the low-torque of the three-cylinder engine is better than that of the 4-cylinder engine. However, the corresponding power attenuation and responsiveness change in the high-speed range. difference.

4. The three-cylinder engine has poor ride comfort and large vibration. The engine uses dynamic balancing technology to reduce vibration. Due to inherent reasons, engines with more than four cylinders can balance each other's vibrations. The ignition phase angle of three-cylinder engines is larger than that of four-cylinder engines. Therefore, although car companies have designed three-cylinder engines Many damping devices use pendulum-type dual-mass flywheels, crankshaft rubber damping, and other technologies, but they still cannot further improve ride comfort, especially when the engine is under load conditions such as cold start and rapid acceleration. The difference in power comes out.

5. A three-cylinder engine has a relatively short service life, a large force on the cylinder, and obvious wear. The three-cylinder engine has obvious congenital vibration. The cylinder and crankshaft are relatively more stressed at the moment. In theory, the wear will be larger than that of a 4-cylinder engine. Will cause the engine life to be affected to a certain extent.

6. Three-cylinder engines can reduce manufacturing costs. For automakers, small size, lightweight, fewer parts, and fewer gas distribution structures will naturally reduce costs.

Nowadays, the three-cylinder engine technology is still in the process of continuous development and improvement. It is limited by the basic structure. Although the smoothness of the three-cylinder engine has been greatly improved during the normal operation process, the three-cylinder engine is still under special working conditions. The engine still has inevitable jitter. Therefore, under the premise of having a choice, I personally recommend that the four-cylinder engine is more reliable.


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