There are certain buzzwords everyone hears when they are buying a car, but perhaps none more so than “torque” and “horsepower.” In a recent article on caranddriver.com, author Don Sherman attempts not only to explain these words, but also the difference between the two.
“The perfect engine produces ample torque at low rpm and sustains that output to the redline,” Sherman explains. “The amount of torque produced is directly proportional to the air flowing through the engine. Large engines pump more air and, therefore, produce more torque. Boosters—superchargers, turbochargers—deliver additional air to help small engines act large. Of course, appropriate amounts of fuel must be supplied to the combustion chambers, but that’s the easy part, especially with electronically controlled injection.”
Now you don’t need to worry if you didn’t quite catch all of that. If we’re being honest, we didn’t even understand it all. That’s why Sherman went on to define the different features that are combined in horsepower and torque.
As he explains, energy is the capacity for doing work, which means they do work that used to be done by horses. Work is the result of a force acting over some distance. This is measured in foot-pounds, joules and newton-meters. Torque is a rotating force produced by an engine’s crankshaft, which roughly translated means that the more torque and engine produces, the greater its ability to perform work.
“Of course, there’s always an exception,” Sherman writes. “In this case the distinction is static torque, the kind you apply with a wrench to tighten head bolts. To avoid confusion, the units for static torque are traditionally foot-pounds. Just to be contrary, SI sticks with newton-meters for both static and dynamic torque measurements.”
He also explains power as the amount of time work gets done, and is explained really well by 18th-century Scottish inventor James Watt. He measured units of power by comparing them to the source of power at the time: horses. According to Watt, one horsepower is the power required to lift 33,000 pounds exactly one foot in one minute. The measurement unit for power is the kilowatt.
“At this point of the discussion, it should be clear that torque and horsepower are like estranged siblings; they’re closely related but don’t have much in common,” Sherman explains. “But what about the greater moral issue confronting mankind in general and car enthusiasts in particular: Which is better?”
His answer may surprise you. He compares the difference between torque and horsepower to a game of baseball. If torque is playing catcher, then the pitcher has the name horsepower written on the back of his jersey. Both are necessary to play ball, but horsepower is what separates a great engine from just a good one.
You can find Don Sherman’s article here.