What's the difference between torque and horsepower?

Most commercials you see for big trucks advertise the impressive amount of horsepower and torque the引擎提供。像往常一样，数字越大，越好。但是这些数字是什么意思，这两个概念如何相关？

The power an engine produces is called horsepower. In mathematical terms, one horsepower is the power needed to move 550 pounds one foot in one second, or the power needed to move 33,000 pounds one foot in one minute. Power, in physics, is defined simply as the rate of doing work.

发动机马力是使用测功机测量的。测功机将发动机的负载放在发动机上，并测量发动机曲轴对负载的扭曲力。负载通常是制动preventing the wheels from spinning.

What the dynamometer is really doing, however, is measuring the torque output of the engine. In a vehicle, torque is measured at various engine speeds, or revolutions per minute (RPM). These two numbers are fed into a formula -- torque times RPM divided by 5,252 -- to arrive at horsepower. The Society of Automotive Engineers has two standards for determining horsepower: net and gross. Gross horsepower removes most loads from the engine, including emission controls, before testing. Net horsepower is what's found by testing the same kind of stock vehicle you'd find at the showroom, and that's the measurement now used in advertising and manufacturer literature.

Horsepower is determined from torque because torque is easier to measure. Torque is defined specifically as a rotating force that may or may not result in motion. It's measured as the amount of force multiplied by the length of the lever through which it acts. For example, if you use a one-foot-long wrench to apply 10 pounds of force to a bolt head, you're generating 10-pound-feet of torque.

如上所述，可以生成扭矩，而无需移动对象。但是，当它确实移动一个物体时，它就会变成“工作”，这就是大多数人在想到扭矩（通常在牵引方面）时想到的。发动机产生的扭矩越多，其潜力就越多。

Read on for more about the relationship between horsepower and torque.

The Relationship Between Torque and Horsepower

Torque and马力play an integral role in the automotive market. The numbers are emphasized as ways of illustrating what a car or truck can do. In reality, the numbers play a more complex role than most consumers realize. More importantly, how the numbers function in the real world of driving andhauling由车辆的设计允许两个概念一起工作的方式来定义。

Remember, torque is the base number for work, and power is the rate of doing more work. The齿轮系统例如，可能会影响发动机内部的工作方式：皮卡车可以具有低齿轮，以将更多的扭矩引导到特定的应用中，例如拖曳非常重的负载。但是，如果在土星SL1上使用相同的齿轮，而RAM 1500，则由于产生的马力差异，RAM将始终能够牵引更多。产生的马力越多，发动机的扭矩潜力就越多。

But that's just what it is -- potential. Torque potential is translated to real-world applications through the vehicle's transmission and axles, specifically the axle differentials. The way these units are geared determines how the horsepower is translated to torque.

To understand this, think of the difference between arace car和tractor. The race car develops an enormous amount of horsepower, but the torque is used for speed through gearing. There's not a lot of work needed, in a relative sense, to push a race car forward, so less work is accomplished, leaving more power for speed.

另一方面，拖拉机可能具有相同尺寸的发动机，产生相同数量的马力。该马力是通过齿轮进行工作的。拖拉机无法达到高速，但它可以拉动并推动大量重量。

下次您看到一辆宣传的车辆television，考虑一下他们谈论马力和扭矩时的含义。两者之间存在着一种关系 - 没有彼此，它们就不可能存在，但是它们代表了制造汽车或卡车工作的非常不同的方面。

最初出版：2011年12月21日

Torque Horsepower FAQ

What is the difference between torque and horsepower?

Torque is defined specifically as a rotating force that may or may not result in motion. The power an engine produces is called horsepower.

您如何测量扭矩？

扭矩被测量为力量乘以其作用的杆的长度。例如，如果您使用一英尺长的扳手在螺栓头上施加10磅的力，则会产生10磅重的扭矩。

您如何将扭矩转换为马力？

In a vehicle, torque is measured at various engine speeds, or revolutions per minute (RPM). These two numbers are fed into a formula — torque times RPM divided by 5,252 — to arrive at horsepower.

Is it better to have more torque than horsepower?

There's a relationship between the two — they can't exist without each other, but they stand for very different aspects of making a car or truck work. The numbers are emphasized as ways of illustrating what a vehicle can do.

Is torque important for towing?

Torque is the base number for work, and power is the rate of doing more work. The gear system, for instance, can affect how work within the engine occurs: A pickup truck can have a low gear to channel more amount of torque into a specific application, like towing very heavy loads.

Lots More Information

Sources

Chamberlin, Ken; Chrysler Master Technician; personal interview; Dec. 7, 2011
Halderman，James D.，Chase D. Mitchell Jr。“汽车引擎：理论和维修；”皮尔逊·普伦蒂斯·霍尔（Pearson Prentice Hall），2005年；PGS。55-58
兰德里，格雷格；克莱斯勒发动机性能专家；个人面试；2011年12月7日

What's the difference between torque and horsepower?