Car Facts You Didn’t Know: What is Horsepower?
If you’ve ever seen a commercial for a truck or a sports car, you’ve probably heard the narrator exclaim just how much horsepower that beast of a vehicle can get. But what is that number and what does it mean? Is it how many horses the car can tow? Is it the number of head nods you’ll receive per year from other dude bros who are impressed by how manly and tough your car is? Let’s check out the origin of the term and what it means for your vehicle.
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A familiar inventor
The term “horsepower” was coined by Scottish inventor and engineer James Watt. You might recognize that last name as the unit of power for light bulbs. Watt was a man of many inventions and processes, having improved upon the Newcomen steam engine with his own iteration in 1776, which was one of the driving forces of the Industrial Revolution. Horsepower came about as a way for Watt to measure the output of those very steam engines. He based it on the power of draft horses, which were used frequently for hard labor.
But what is horsepower?
Simply put, “horsepower” is a unit of power equal to 550 foot-pounds per second. But that’s not really helpful now, is it? Let’s try an example. One unit of mechanical (aka U.S.) horsepower, or hp, is equal to 745.7 watts. That means 1 hp could power approximately 18 40-watt bulbs. If we multiply those 18 bulbs by the 2021 BMW M8 Coupe’s 600 hp, that totals 10,800. What this means is that the M8 Coupe could produce enough power to burn more than 10,000 40-watt light bulbs when reaching its full horsepower potential. For reference, the very first Times Square New Year’s Eve ball used 100 25-watt bulbs.
Photo: M. Maggs via CC
What does it all mean?
Okay, cool. Now we know what horsepower is and how it’s measured. But what does it mean for your car? Combined with the RPM (revolutions per minute) of a car’s various mechanical components, more horsepower helps a vehicle accelerate faster, increases its towing capacity, and typically increases fuel usage. That means those trucks with a ton of horsepower that can tow a boat or RV usually have lower fuel economy as a result. Ta-dah!
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Of course, with any explanation of mechanical components in a vehicle, it’s never that simple and there are additional factors and systems to consider. But the goal of this article was to help put horsepower in layman’s terms enough to help people make a more informed decision during the car-buying process. I hope it helped!
Ben never thought he’d be writing about cars for a living, but here he is, knowing more about the Kia Stinger than he’d care to admit. When he’s not devoting his time to researching engine specs and other oh-so-exciting car details, he can be found enjoying time with his wife and dogs. See more articles by Ben.