What's the Difference between Torque and Horsepower?

When you want to compare different cars, you may look at their engine performance. This is described in horsepower and customers assume that a higher number means the engine is more powerful. While this can be true, another number to consider is the torque.

Torque is simply the measure of any twisting force that the motor or engine can produce. This rotating force can then be applied to the transmission and the gears that are inside before getting sent to the wheels. The two numbers are related to one another, though they are different.

How are Horsepower and Torque Different?

To start, we need to look at how these are different. Horsepower is simply the measure of how much work is done over a set period of time. So, one horsepower is basically how much effort is needed to lift up 33,000 pounds in one minute a total of one foot.

Since a car maker does not have a ton of blocks that are 33,000 pounds lying around to check out what the horsepower actually is, they will use a tool known as a dynamometer to measure the torque of the engine based on the different speeds. There are a few calculations that take the numbers from the torque, as well as the RPM of the engine, to figure out the horsepower.

The number that the manufacturers are likely to publish will be the maximum points on the graph along with the engine speed that these maximum points occur. Since the toque, and therefore the horsepower, will change as the speed of the engine goes up, there is often a full graph of possible answers.

Which One Should I Look At?

Whether you look at the torque or the horsepower really depends on what you want out of the car. For example, if you want to tow, then having an engine with a higher torque is the best. This is what you see with diesel engines. But if you want to go fast, then the horsepower is a better indicator of what you want. You are likely to look at torque with a truck while a sports car will focus more on the horsepower.