The definition of the power of a vehicle
The power of a vehicle refers to the maximum power delivered by its engine. It is expressed in Watts, in Horsepower (hp) or in DIN Horsepower.
Power depends on two forces
In an automobile, power depends directly on two other forces: torque, expressed in Newton Meters (Nm), and engine speed, expressed in revolutions per minute (rpm). Since the power is most often expressed in horsepower (hp), it results from the following operation:
Power (hp) = Torque (Nm) x Speed (rpm) / 7000
Understanding the unit of measurement HP
The unit of measurement ch corresponds to the name Horse-steam-electric, created at the end of the 18th century in order to compare the power of steam engines with that of horses. This unit of measurement represents the power of a horse pulling 75 kg at a walk, or the equivalent of one meter per second.
Note that a vehicle can be very powerful without having a high torque. This means that it will take more turns in order to reach the right power, to change gears for example. If the car has a high torque, it will need fewer revolutions to obtain the desired power.
Difference between engine power and tax horsepower
Engine power (hp) should not be confused with fiscal horsepower (CV), also called tax horsepower or administrative horsepower. The CV is a unit of measurement that is simply used to calculate the registration tax of the vehicle according to its engine power and its carbon dioxide emissions.
