What Does Horsepower Mean in a Car?

December 4, 2023

If you’re in the market for a new car, then you’ve probably been thinking about what type of horsepower is right for you. After all, horsepower impacts a lot of factors beyond top speed and having the right number can make your vehicle feel more powerful and nimble.

In order to determine a vehicle’s power, manufacturers use a device called a dyno that measures how much work the engine can do and then turns that into the number of horsepower. However, many people confuse horsepower with torque and it’s important to know the difference.

The term “horsepower” was coined in the late 18th century by James Watt as a way to compare the performance of his steam engines with draft horses. Watt’s definition equated one horsepower to the amount of energy expended by a single animal lifting 33,000 pounds one foot in the air from the bottom of a 1,000 foot deep well in one minute.

These days, manufacturers no longer plant their cars in front of a well in order to measure power and instead opt for more accurate dyno tests. They also switch from crank horsepower (which is a figure based on the power being put out at the engine’s crankshaft) to wheel horsepower, which is a more accurate number that reflects how much power actually makes it to the wheels.

In Europe, the metric that is used most often is kilowatts (kW), which is the same as horsepower but with a different formula. However, most of us still see bhp numbers listed on car specs and it’s worth remembering that 1kW is equal to about 1.3hp.

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