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Blog Horsepower vs. Torque (Getting Up to Speed and Staying There)

Horsepower vs. Torque (Getting Up to Speed and Staying There)

May 5, 2020

Every description of a car, truck, or SUV includes information about engine power, but what is horsepower versus torque? Horsepower and torque do several important things:

In every case, engine power is calculated and expressed with two different numbers: horsepower and torque. Everyone knows the two numbers are related, but most aren’t clear on what they represent. We’ve got a simple explanation that should clear things up.

What is Torque?

Horsepower and torque are both measurements of engine power, but they measure that power differently. Here’s how it works:

The pushing force of the runner’s legs is like torque. If you put a scale between the runner’s shoe and the ground, you could measure the amount of force being applied with each step. Just as leg torque accelerates the runner, engine torque accelerates a vehicle. Here’s what you need to know about torque:

Remember this: More torque helps a vehicle achieve a fast 0-60 time.

What is Horsepower?

Question:Why doesn’t the runner continue accelerating forever?

Answer: Because there’s a limit to how fast the athlete can move his or her legs. There’s also some drag because of gravity and wind resistance. Eventually, the runner is running as fast as possible, and drag prevents any further acceleration. It’s the same with engines. Here’s what you need to know about horsepower:

Remember this: Because of the math involved in calculating the values, torque and horsepower are always the same at 5,252 rpm.

Why horsepower and torque are important

When people read engine ratings, they tend to focus on horsepower because it’s a simple number that corresponds to how “fast” the vehicle will be. In fact, torque is usually more important when it comes to driving in the real world. That’s because we do so much accelerating from stoplights and stop signs. Drivers experience torque in the following ways:

Drivers experience horsepower in these ways:

Remember this: Diesel engines produce more torque, but comparatively less horsepower.

Relating horsepower and torque to performance

Drivers expect vehicles with high torque and horsepower ratings to be fast and accelerate quickly, and that’s generally true. However, vehicle weight and aerodynamics are also important factors. Just like our imaginary runner, gravity and wind resistance affect your vehicle’s performance. Here’s what you need to know about performance:

Remember this: Performance depends on many factors, including size, weight, and engine power.

Relating horsepower and torque to fuel economy

Just like performance, you should be aware that there’s a direct relationship between torque and horsepower and a vehicle’s fuel economy.  Once again, weight and aerodynamics have a profound effect on your vehicle’s efficiency. When you’re evaluating different vehicles, here’s what you need to know about fuel economy:

Remember this: Engine power always comes with a price. You have to burn more fuel to get more power.

What about hybrid and electric vehicles?

The most important benefits of hybrids and EVs come from their electric motors. These motors not only save fuel, they provide excellent torque. Electric motors can replace internal combustion engines, or they can add to the torque from an internal combustion engine. Here’s what you need to know about electric motors:

Remember this: Electric vehicles are great for quick acceleration.

What about turbocharged vehicles?

One way you can make more torque and horsepower is by adding a turbocharger or supercharger to an engine. These devices force pressurized air into the engine, which also means more fuel must be burned. Putting in more air and fuel means more power is produced. Here’s what you need to know about turbocharged motors:

Remember this: Turbocharged engines operate under more stress than normal engines.

Evaluating torque and horsepower when you choose a vehicle

When you’re going to buy a new or pre-owned vehicle, horsepower and torque make a big difference. However, don’t just buy the vehicle with the biggest numbers. Look at the whole package including the size and weight of the vehicle, the transmission, and fuel economy. For example, consider two vehicles:

This truck weighs 7,700 pounds. The F-350 has a 6.7-liter Power Stroke turbo-diesel engine with 935 pound-feet of torque and 450 horsepower.

This car weighs 2,337 pounds. The Miata has a 2.0-liter engine with 181 horsepower and 151 pound-feet of torque. 

The bottom line on horsepower and torque

Most people talk about vehicle engines in terms of horsepower. They’re not wrong; it’s an easy shorthand for overall performance. In terms of buying a new or used vehicle, it’s best to look at your needs before making a choice based on the engine’s rating numbers. The characteristics of torque are:

The characteristics of horsepower are:

Most people will tell you they like engine power, but what they really like is a vehicle that has well-balanced torque and horsepower. The right amount of horsepower and torque is enough to accelerate quickly, but not too much. Too much power places the driver in danger of spinning the tires or losing control of the vehicle. When you think about horsepower versus torque, the most important thing to remember is that they aren’t in conflict. Torque and hp work together to give your vehicle the performance you need. Any runner could tell you that.