Okay, so I was messing around with some engine specs the other day, and I got totally confused about the different power units. You know, horsepower, PS, kilowatts… it’s a mess! So, I decided to dig in and figure out what’s what, especially when it comes to imperial units.
Figuring Out the Basics
First, I had to get the basics straight. I started by looking up what exactly “horsepower” even means. Turns out, it’s all based on this old idea of how much work a horse can do (duh!).
The imperial horsepower, the one we mainly use, is defined as the power needed to lift 550 pounds by one foot in one second. or do the work 33,000 */min. I wrote that down to make sure that I could remember it.
Then I realized there are a bunch of other units that sound similar. There’s “PS”, which is a metric horsepower. And of course, there are kilowatts (kW), which are also metric and part of the SI system (that international standard thing).
My Little Experiment
To really get a feel for this, I took a few car engine specs I had lying around. One was listed in horsepower (hp), another in PS, and another in kW. I wanted to see if I could convert between them all, using only imperial units where it made sense.
- Example 1: A car listed as having 200 hp. Easy peasy, that’s already in imperial horsepower.
- Example 2: An engine rated at 150 PS. This is where it gets a little tricky. I used my phone to converted it,150 PS to hp, it’s about 148hp.
- Example 3: An electric motor rated at 100 kW. Okay, first,I also converted kW to hp, the result is about 134hp.
Putting It All Together
So, after all this, I’ve basically got a better handle on how to compare these different power units. While my calculations were with my phone and weren’t super scientific, I will do the accurate calculation when I need them.
In short. My way to keep things straight, especially with imperial units, is to: always convert everything back to horsepower (hp). It’s my go-to, familiar unit, and it makes comparing different engines much simpler. I should have a clearer convert table, but this is a rough record for today.