The RPM of an engine is the speed at which it rotates. It’s measured in revolutions per minute (RPM).
The engine’s power output is directly related to its RPM. As you increase the RPM, more power can be generated. If you increase the RPM and keep torque constant, power increases as well. At very high RPMs, though, engines are prone to “overheating” and “pinging” (detonation).
The reason why the engine goes up and down in RPM is because of compression and expansion of air inside the cylinder. When an internal combustion engine burns fuel in a cylinder, the burning process generates heat that causes an increase in pressure within the cylinder. This increased pressure compresses the air inside, forcing it into a smaller space than before. This happens over and over again until all of the fuel has been burned and forced out through an exhaust valve into an exhaust pipe connected to another pipe that leads outside of your car.
Last modified: September 18, 2022