Have you ever wondered why your car’s energy output is measured in units of horsepower?

Before the advent and use of mechanical engines, animals were used to supply power to different systems. As a result, the term horsepower was coined and applied to steam engines, and those that followed. Today the Brigham City car repair team from Master Muffler shares some insight on the history of horsepower.

How Much Horsepower is in a Horse?

Draft horses, known for their strength, were a common option for getting work done. It is estimated that one “horsepower” unit from a draft horse provides 745.7 watts of energy. This is calculated by determining the relationships between torque, pounds moved, and rotational speed.

Horsepower can be further broken down into different types of energy, including:

  • Mechanical Horsepower
  • Metric Horsepower
  • Tax Horsepower
  • Electrical Horsepower
  • Hydraulic Horsepower
  • Boiler Horsepower
  • Drawbar Horsepower
  • RAC Horsepower

Horses themselves are rated about 15 horsepower each, which may be confusing. Why doesn’t one horse equal one horsepower? It’s simply the result of the average horse’s output throughout a single working day. 

Horses vs Engines

In the 1800s, steam engines began doing some of the work previously reserved for horses. To help mine owners and operators understand what they were getting, they would often inquire how many horses the engine was replacing. Thus, steam engine energy was measured in comparison to the power of draft horses.

How Is Horsepower Determined?

Scottish inventor and engineer James Watt developed the unit of measurement for the steam engine he was trying to sell. He wanted businesses, such as the hypothetical miners mentioned above, to understand the benefits of switching to steam-powered engines in their operations.

Watts decided to measure the work being done by draft horses in order to find a way to compare it to his product. Here’s a look at the data he needed to consider to make his calculation:

  • Horses walked in circles measuring 24 feet in diameter.
  • Horses made the circle about 144 times every hour.
  • Each horse pushed with an estimated 180 pounds of force.

With this information, Watts determined each workhorse was doing 33,000 foot-pounds of work every minute. What’s a foot-pound of work? A foot-pound is equivalent to lifting a 33-pound bucket of water out of a 1,000-foot-deep well in just one minute. Horsepower can also be explained as the amount of power needed to move 550 pounds the distance of one foot in one second.

How Does Horsepower Translate to Vehicles?

You may be wondering what horses and steam engines have to do with cars. Well, as engineering advanced and more people considered switching from actual horsepower to engines for running mines and mills, the measurement of horsepower could be applied to vehicles as well.

In driving, horsepower and torque are two different elements; torque is the force applied, whereas horsepower is the work’s rate. An engine may boast amazing horsepower but have less torque. This will translate to an engine that can sustain higher revolutions per minute (RPM) while maintaining speed but may feel slow to start. If you want a car that accelerates quickly off the line and can sustain high RPM, you want to look for more torque and horsepower.

Horsepower in Early Engines

Remember how one horse has a 15 horsepower rating? Let’s compare that to some of the vehicles introduced in the early 1900s.

  • 1903 Ford Model A – 8 horsepower
  • 1908 Ford Model T – 20 horsepower
  • 1929 Hudson 7 Roadster – 92 horsepower

Until the 1920s, you might be better off riding a horse than a motor vehicle when it came to power. However, horse repair might be a little more cumbersome than car repair in those days.

Average Car Horsepower

So, how much horsepower do you need under your hood? Depending on what kind of performance you want, you can invest in a variety of horsepower ratings. Here’s a look at some of the top-selling cars of 2020, and what they’re rated when it comes to horsepower.

  • Toyota Corolla – 132 horsepower
  • Honda Civic – 158 to 180 horsepower
  • Nissan Rogue – 170 horsepower
  • Toyota Camry – 178 to 301 horsepower (four-cylinder engine vs V-6)
  • Nissan Altima – 182 to 248 horsepower
  • Honda CR-V – 184 to 190 horsepower
  • Ford F-Series – 290 horsepower
  • Chevy Silverado – 355 horsepower

On average, mid-sized, domestic cars offer between 180 to 200 horsepower. To efficiently maintain its rate of speed, a vehicle should have at least 10 horsepower. Added bells and whistles on a car require additional horsepower to keep things running, both literally and figuratively. The car needs to maintain speed, while the AC, radio, lights, and other electronic features need power as well.

How Much Horsepower Do I Need?

Now that you know what the average horsepower is, how much do you actually need? Brigham City car repair experts recommend anywhere between 200 and 300 horsepower. This will allow your vehicle to travel efficiently and have enough power for all its systems.

If you drive a diesel-powered vehicle, your engine will automatically have more torque, which means it can work harder than a gasoline-powered car with less effort. However, it doesn’t mean a diesel accelerates faster or has more power; a vehicle requires more horsepower to work faster.

How Horsepower has Improved

Horsepower can be improved with aftermarket modifications to your vehicle but, obviously, cars today already come with a big improvement over the 8 horsepower Model A. How has horsepower improved over the years?

  • Better air intake
  • More efficient exhaust systems
  • Better catalytic converters
  • Lighter weight cars
  • Adding super- or turbochargers
  • More sophisticated automotive software

For Brigham City car repair (sorry, we don’t service horses!), or aftermarket installs, give us a call today.