The notion of horsepower has long since outlived its usefulness. If you’ve got 12 minutes, here’s an excellent explanation.

Developed by Scottish inventor James Watt way back in the 18th century, the concept of horsepower is a fascinating bit of engineering technology with an equally fascinating history. And among American automotive enthusiasts, the term has almost magical properties. Horsepower: It’s our favorite subject. But to be perfectly honest, the horsepower (550 ft-lbs work per second, hp = Fd/t) is an arbitrary and cumbersome way to measure the output of a road vehicle. (There are even regional variants, which make even less sense.) These problems shouldn’t be much of a surprise, since when Watt came up with the idea, the automobile and the internal combustion engine as we know them did not yet exist. Here is the 21st century, horsepower is a little crazy, no offense.

Evidently, all this has also been on the mind of YouTube tech guru Jason Fenske of Engineering Explained. In this video, a fast-paced 12 minutes, he explains the origins and function of horsepower, and then he demonstrates a far more sensible way: the watt, which is indeed named in honor of our Mr. Watt (so it’s all good.) Watts and kilowatts have long been the preferred units of power in the engineering world, but we car enthusiasts, we cling to our traditions. Long story short, one British Imperial horsepower is equal to 745.7 watts, or .745 kilowatts if you will, and here Jason demonstrates how the SI (International Systems of Units) method is, once you embrace it, a far more useful approach. Video below.