Horsepower: the Dummy Version

Definition of one horsepower

If you're even slightly interested in cars, chances are pretty good you're familiar with the BBC show "Top Gear." Well, the principals of that show were all shown the door in 2015, and all three of them – Jeremy Clarkson, Richard Hammond and James May – are now doing pretty much the same show for Amazon. It's "The Grand Tour." Our car guy was watching the pilot episode one day and noticed that the visuals displayed a car's power as BHP, which got him wondering what those drones at eHow.com (now Leaf Group) think of that abbreviation. Sure enough, it was dumbassery: specifically eHowian Cheryl Ess (fake name, for obvious reasons) and her post titled "How to Convert BHP to HP" over at Sciencing.com.

The answer to that query is simple: you can't. They're the same quantity measured different ways, and more to the point, have multiple different meanings in North America and Europe. So when Ms S... errr, Ess decided to explain how to do this, she was already on shaky ground. That ground got even shakier when she started saying crap like

"Determine exactly which bhp you are starting with. If you are dealing with a boiler, it is boiler horsepower..."

Give us a break, Cheryl! Boiler horsepower? converted to mechanical horsepower? Not likely! And then Cheryl ultimately displayed her complete ignorance of not only horsepower, but how to answer "how-to" questions: "Enter the numeric value of the unit of horsepower you started from. You may also need to select the unit of horsepower you are starting from and/or the unit to which you are converting. Different conversion sites operate slightly differently. Some sites offer additional parameters, such as number of significant digits. You either hit 'Enter' or click on a button to display the converted numeric value. "

Now, we know why S... errr, Ess did that: we couldn't find a formula for converting between the two numbers, except perhaps a rather complicated explanation we found on Quora.com:

"Brake Power B is -
   B = (I1-L1) + (I2-L2) + ….. (depending on number of cylinders)
After shorting of spark plug , B1 = (0-L1) + (I2-L2) + … (Since, the spark plug is shorted, Indicated power is zero but frictional losses still exist, so L1 persists)
Thus , I1= B-B1
This process can be repeated for every individual cylinder. The net Indicated Power can be obtained as -
I = I1+I2+I3+…."

...which, we think, should be something a self-described "engineer" should be able to comprehend and even repeat. But Ess couldn't, instead offering a couple links to black box conversion sites, neither of which even attempt to convert BHP to HP. We call "bushwa!" and thus we name Cheryl Ess our Dumbass of the Day again. Interestingly, this is her second award out of four eHow posts... oops.

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