0
By Karl Brauer, Editor in Chief, Edmunds.com While horsepower is often considered when shopping for a vehicle, what about that "other" engine rating: torque? Specifically, what are the differences between horsepower and torque? If you flip through the pages of any automotive publication, you'll notice that these two measurements are commonly listed under vehicle specifications. And while the average car enthusiast knows that both horsepower and torque play a role in performance, most of them don't understand exactly how or why. Let's begin by explaining the technical difference between the two. Horsepower is defined as the amount of energy required to lift 550 pounds, one foot, in one second. From this definition you can see that the components of horsepower are force, distance and time. Distance and time are self-explanatory but force, specifically a twisting force, is what torque is all about. Remember that the initial energy that moves a car forward starts in the combustion chamber in the form of an explosion. This explosion forces a piston (or group of pistons) down in a straight line, which pushes on a connecting rod and turns the engine's crankshaft. It's this turning crankshaft where the twisting force of torque initiates. From there the force is carried through a flywheel, transmission, driveshaft, axle(s) and wheel(s) before moving the car. The measurement of torque is stated as pound-feet and represents how much twisting force is at work. If you can imagine a plumber's pipe wrench attached to a rusty drainpipe, torque is the force required to twist that pipe. If the wrench is two feet long, and the plumber pushes with 50 pounds of pressure, he is applying 100 pound-feet of torque (50 pounds x 2 feet) to turn the pipe (depending on the level of rust, this may or may not be enough torque). As you may have noticed, this measurement of torque does not include time. One-hundred pound-feet of torque is always 100 pound-feet torque, whether it is applied for five seconds or five years. So, if you want a quick answer to the difference between horsepower and torque, just keep in mind that horsepower involves the amount of work done in a given time, while torque is simply a measurement of force and is thus a component of horsepower. To see how torque and horsepower interact, imagine your favorite SUV (everyone has one of those, right?) at the base of a steep hill. The engine is idling and the gear lever is in the "Four-Low" position. As the driver begins to press on the throttle, the engine's rpm increases, force is transmitted from the crankshaft to each wheel, and the SUV begins to climb upward. The twisting force going to each wheel as the vehicle moves up the hill is torque. Let's say the engine is at 3,000 rpm, the gear ratio is 3, and the vehicle is creating 300 pound-feet of torque. Using the following formula, we can calculate horsepower: Take the torque of 300 multiplied by a shaftspeed of 1000 (3000 rpm divided by a gear ratio of 3) for a total of 300,000. Divide 300,000 by 5,252 and you get 57.1 horsepower that the SUV is making as it begins to ascend the hill. It is interesting to note that, since 5,252 is used to calculate horsepower by way of torque and shaftspeed, it is also the number in the rpm range at which torque and horsepower are always equal. If you were to view the horsepower and torque curves of various engines, you would notice that they always cross at 5,252 rpm. So now we have a technical understanding of how torque interacts with horsepower, but let's move beyond that to some real-world examples. For instance, we all know that a car moves from a dead stop in 1st or low gear, yet as the car's speed increases, the gears must be moved up through 2nd, 3rd and 4th to maintain acceleration. This is because at low speeds the transmission's gears work to transmit maximum torque from the engine to the wheels. You want this because it takes more force, or torque, to move a vehicle that is at rest than it does to move a vehicle in motion (Newton's 1st Law). At the same time, once a vehicle is underway, you want less torque and more horsepower to maintain a high speed. This is because horsepower is a measurement of work done and includes a time element (such as wheel revolutions per minute necessary to maintain 75 mph). Since entire books have been written on the concepts of horsepower and torque, it's not realistic to try and cover them fully in a single column. Finally, let me leave you with my favorite phrase about the relationship between horsepower and torque: Horsepower is what you read about, torque is what you feel.
What else can I help you with?
How is horsepower actually calculated?
Horsepower is typically calculated based on the formula: horsepower = (torque x RPM) / 5252. Torque is measured in pound-feet, and RPM is the engine speed in revolutions per minute. This formula allows for the conversion of torque and engine speed into a measure of power output.
What is the difference between torque and horsepower?
Horsepower - power over time, continuously used. You can only generate what you need or use.Torque- Power on hand, waiting for demand. Like a weight hanging on stick. It is there when you need it.Torque gets you going and Horsepower keeps you rolling.AnswerYou really should be asking, "What is the difference between torque and power?"Horsepower is simply the Imperial unit of measurement for power, usually used to describe the output (rather than input) power of a machine. These days, most countries use watts, which is the SI unit for power. Power is defined as the rate of doing work. In Europe and elsewhere outside North America, the output power of a car engine is measured in kilowatts, rather than in horsepower.Torque is the product of the radius of rotation and the force acting at right angles to that radius. So, torque is normally expressed in newton metres.The work done by torque can be determined by multiplying the force acting at right angles to the radius, by the circumference through which that force acts. If we know the time taken to complete the circumference, then it is possible to determine the power.
What is the relationship between torque and slip?
Torque in an induction motor is proportional to slip, which is the difference between the synchronous speed and the actual rotor speed. As slip increases, torque also increases, up to a certain point. This relationship is key to understanding the motor's operating characteristics.
What is mean resisting torque in turning moment diagram?
The resisting torque in a turning moment diagram is the torque opposing the applied torque or force, usually due to friction or other resistance in a system. It is represented by the downward curve or line in the turning moment diagram, indicating the counteracting force against the applied torque. The difference between the applied torque and resisting torque determines the net torque or moment acting on the system.
How do you calculate horse power of a steam engine?
Horsepower is defined as work done over time. The exact definition of one horsepower is 33,000 lb.ft./minute. Put another way, if you were to lift 33,000 pounds one foot over a period of one minute, you would have been working at the rate of one horsepower. In this case, you'd have expended one horsepower-minute of energy. There are other definitions but as a whole they say approximately the same as in energy consumed for actual work.
Difference between horsepower and torque?
Torque is the measurement of turning force. A wrench applies torque to a bolt. A motor or engine provides torque to do work. Horsepower is the measurement of the work done or ability to do work. This is done by taking the speed the engine is operating at (RPM) and what torque it is producing and applying a formula to give a horsepower rating.
What horsepower is 18.5 gross ft pounds of torque?
There isn't a direct conversion between horsepower and torque in foot-pounds. Horsepower is a measure of power, while torque measures rotational force. Horsepower can be calculated using a formula that includes torque and engine speed.
What is the horsepower and torque on 1991 Chevrolet 454 engine tonawanda engine?
The horsepower of a 1991 Chevrolet 454 cubic inch engine ranges between 240 horsepower and 350 horsepower the engine torque ranges between 700 pounds and 850 pounds.
What is the difference between a 1000 and 500 when it comes to motorcycles?
A 1000 is known as a liter-bike or 1000cc motorcycle. A 500 is a 500cc or half-liter-bike. cc means cubic centimeters which is the size of the piston(s). The difference between, at present circa 2010, a 1000cc and a 500cc motorcycle is size, weight, horsepower and torque; the 1000 is going to have 150+/- horsepower and 115+/- Nm(newton meters) ft/lbs. of torque; the 500 will have around 50+/- horsepower, 30+/-Nm(newton meters) ft./lbs. of torque.
How much horsepower and torque for an l32?
260 horsepower 280 torque
How much horsepower is 4.50 torque?
Torque is "twisting power" whereas horsepower is motivational. They do not directly translate. Had to guess it is between 4HP and 6HP. Sorry but precision is no available!
How much torque can you get with 400 horsepower?
Torque(lb/ft) = (5252 * horsepower) / RPM
What is the horsepower and torque of a suzuki boulevard c90?
what is the horsepower and torque of the suzuki boulevard c90
How many horsepower is 6.25 gross torque?
Torque and horsepower are two separate ratings.
Why is the relationship between torque horsepower and RPM not linear In automobile terms.?
It is, Horsepower = Torque x RPM, but Torque is not constant across the rev range of an engine. For gasoline engines, there is generally very little torque at low rpms, generally flat torque across the middle rpms, and then a drop off as the engine starts spinning too fast for complete combustion. Electric engines, on the other hand, start off with maximum torque and decrease with higher engine speed. So, the short answer to your question is that it's a direct relationship between horsepower and torque, but the variation in the torque curve across the rpm range makes the resultant horsepower curve vary too. (If your question was really why does torque vary with rpm, simply stated it's because engines have varying efficiencies at different speeds.) It is, Horsepower = Torque x RPM, but Torque is not constant across the rev range of an engine. For gasoline engines, there is generally very little torque at low rpms, generally flat torque across the middle rpms, and then a drop off as the engine starts spinning too fast for complete combustion. Electric engines, on the other hand, start off with maximum torque and decrease with higher engine speed. So, the short answer to your question is that it's a direct relationship between horsepower and torque, but the variation in the torque curve across the rpm range makes the resultant horsepower curve vary too. (If your question was really why does torque vary with rpm, simply stated it's because engines have varying efficiencies at different speeds.)
What is the difference between dynamic torque and static torque ratings?
One difference between dynamic torque and static torque is the level of difficulty to measure. Static torque is each to measure, while dynamic torque is not. This is because it requires a transfer of an electric or magnetic effect.
What is the difference between brake horsepower and horsepower?
The difference between brake horsepower and horsepower or wheel horsepower, they are the same thing, is that brake horse power is the power produced by the crank. The wheel horsepower is the amount of power delivered to the wheels. Brake horsepower refers to the method used to test the engine. A brake is attached to the engine and used to maintain the engine at a constant RPM at full throttle. The delivered power output is then a simple calculation of RPM times torque. Horse power is based on the average amount of work that a horse could do in a day. It is taken to be 746watts. well you guessed it engine output is also specified in kilowatts so divide by 746 and you have horsepower. As stated above it is all the same thing. There is a difference between advertised horsepower and brake horsepower. Advertised horsepower is what a manufacturer will rate its engine/automobile/machine to produce. Brake horsepower is the actual measured horsepower, for example, of a motor on an engine dynamometer.
