Engine power

Power is the product of torque and angular velocity:^[1]

Let:

• ${\displaystyle P=}$ Power in Watt (W)
• ${\displaystyle M=}$ Torque in Newton-metre (N·m)
• ${\displaystyle n=}$ Crankshaft speed per Second (s⁻¹)
• ${\displaystyle \omega =}$ Angular velocity = ${\displaystyle 2\pi n}$

Power is then:

${\displaystyle P=M\cdot \omega }$

In internal combustion engines, the crankshaft speed ${\displaystyle n}$ is a more common figure than ${\displaystyle \omega }$, so we can use ${\displaystyle 2\pi n}$ instead, which is equivalent to ${\displaystyle \omega }$:^[2]

${\displaystyle P=M\cdot 2\pi \cdot n}$

Note that ${\displaystyle n}$ is per Second (s⁻¹). If we want to use the common per Minute (min⁻¹) instead, we have to divide ${\displaystyle n}$ by 60:

${\displaystyle P=M\cdot 2\pi \cdot {n \over 60}}$

• List of production cars by power output

• Böge, Wolfgang (2017), Alfred Böge (ed.), Handbuch Maschinenbau (in German), Wiesbaden: Springer, ISBN 978-3-658-12528-8

• Böge, Alfred (1972), Mechanik und Festigkeitslehre (in German), Wiesbaden: Vieweg, ISBN 9783528140106

• Kemp, Albert W. (1998), Industrial Mechanics, American Technical Publishers, ISBN 9780826936905

• Fred Schäfer, Richard van Basshuysen, ed. (2017), Handbuch Verbrennungsmotor (in German), Wiesbaden: Springer, ISBN 978-3-658-10901-1