What is the difference between power and torque? Why is each important?
by 
Answerbag Staff
ANSWERS: 3
-
The easiest way to think about torque is to imagine a long lever attached to the engine output. The amount of effort that the engine produces to turn this lever is the torque.If you imagine a lever about a foot long and hang a weight of about 1 pound then the equalivent torque would be described as 1ft lb If you have ever used a torque wrench then you can see how much effort you are putting into the wrench with the settings. Torque is not affected really by time though whereas power is.. When he refer to power we usually talk about horsepower and this is measured over time. 1 horsepower can move 33000 pounds 1 foot in a minute (or 550 pounds a second) brake horsepower is measured usually at the crank and a brake is applied to the engine the more braking required shows the engine is developing more torque. Due to friction and other forces though the power output at the drive wheels will be less than the reading at the crank.
-
Torque is a measurment of force, usually in foot-pounds. Power is (Force divided by Time). This can be measured in Foot-pounds per second, but is commonly measured in Horsepower; 1 HP = 550 ft-lb/sec. In the context of car engines, power is the product of both torque and RPM. A handy equation: HP = ( Torque * RPM ) / 5252 Despite advertising to the contrary, torque is what REALLY allows trucks to haul heavy loads and cars to accelerate quickly. However, more torque at the same speed equals more power, and power is what everyone wants. There is an old saying that goes, "People buy horsepower, but they drive torque." Torque is force, and force causes acceleration. Power is marketing, and marketing causes poverty. For a more complete answer, go to http://www.vettenet.org/torquehp.html . Their opinion differs slightly from mine, as they have a bias towards drag racing and outright speed runs while I am more of a rally-racer, which means that my requirements are different. However, they are giving an answer that is correct and factual.
-
What you basically need to know is that torque is the actual grunt of the engine (hauling loads, getting off the line power...) while horsepower is the power to keep the vehicle moving (for passing at high speeds, climbing at high speeds, maintaining speeds... Each is important because without torque you would not be able to start on a hill without flooring it and it would be impossible to spin the tires of a car. Without horsepower, the engine would have a hard time maintaining high speeds, passing on highways, etc.
RELATED QUESTIONS
Copyright 2023, Wired Ivy, LLC