- How does horsepower work?
- How does it differ to other power units?
- Parkers explains the ins and outs
HP (horsepower) is a unit used to measure a vehicle’s power output. Horsepower is the German translation of pferdestarke (usually abbreviated to ps) and is therefore the same unit of measurement.
Not to be confused with imperial brake horsepower (bhp), which, although also used to measure a vehicle’s power output and often a similar figure, is a different type of unit (1bhp = 0.9863hp).
How does horsepower work?
A vehicle’s horsepower is measured as the power output from the engine, or crankshaft. This will be slightly greater than the amount of power the vehicle is putting down on the road because there are always frictional losses in the transmission between engine and tarmac.
Maximum power is usually expressed in this style: 120hp @ 6,000rpm, signifying how hard the engine is working when it delivers peak power.
Do I need it?
Yes. Without power, your vehicle will not move! Having said that, pure electric cars measure their power output in kilowatts (kw) instead of horsepower.
All combustion-powered vehicles in production generate horsepower. Not to be confused with torque, which is the measure of how hard a vehicle can pull.