: How is the Horsepower of a car measured? And how did they measure it for the firsts motored cars?

Question

: How is the Horsepower of a car measured? And how did they measure it for the firsts motored cars?

In: Engineering

Answer 1

How is it measured today? They measure how much power the engine puts out in kW, then convert it into the archaic unit of “horsepower”.

How was it first measured? Apparently they lifted weights with a specific speed to a specific height. For each 33000 American Pounds lifted by 1 foot of height over the timespan of one minute, the car was declared to have 1 horsepower. I assume that is what their “standard horse” was capable of lifting, hence the strange numbers.

Nowadays a horsepower is simply defined as 746 Nm/s or 746 W