What is horsepower, exactly?

Car dealers and advertisers often talk about horsepower. If you’ve ever wondered what this term means, here’s what you should know.

Why it’s called horsepower
Horsepower (hp) is the theoretical power that one horse can generate. The term was coined in 1782 by Scottish inventor James Watt, who, based on his observations at a coal mine, determined that a horse was capable of accomplishing 33,000 foot-pounds of work per minute, which meant it could pull 330 pounds of coal 100 feet per minute.

The typical mid-size car has about 170 hp. This means that the maximum power it can generate is equivalent to the force produced by about 170 horses.

Why horsepower is important
Horsepower is the most useful metric for measuring engine performance. Greater horsepower translates to faster vehicle acceleration and higher speeds. Plus, along with torque, horsepower is vital to towing capacity.

Why cars need so much of it
Compared to Watt’s horses, which hauled heavy mounds of coal at a modest pace, your car engine powers a massive load, with the average mid-size car checking in at around 3,300 pounds. In addition, you need to travel much faster. This requires the power of a lot of horses.

Finally, in case you were wondering, the car with the most horsepower is the Lotus Evija, which has a stampede of 1,973 horses under its hood.

The math of horsepower
Horsepower is calculated as follows: force (in pounds) multiplied by the distance (in feet) divided by time (in seconds).