Power: how fast work happens
Two engines show the same torque. Is that enough to compare their power?
Power measures how quickly work is done. Horsepower and kilowatts are units of power. Engine power depends on both torque and rotational speed, so the largest torque number alone cannot tell you the largest power output.
Power describes how quickly work happens. At a particular operating point, both torque and rotational speed matter.
Mechanical horsepower (hp) and metric horsepower (PS) are different units. Always keep the stated unit when comparing factory specifications.
At a given engine speed, more torque means more power. At a given torque, more rotational speed also means more power.
Think it throughEngine A makes 200 Nm at 1,500 RPM. Engine B makes 200 Nm at 3,000 RPM. Which has more power at these points, and by what factor?
Show the reasoning
B has twice the power at the stated point: the same torque acts at twice the rotational speed. This comparison does not establish either engine’s peak power.
- Ask for torque and RPM at the same operating point.
- Keep kW, hp or PS attached to the quoted figure.