What is torque and why is torque more important than horsepower?


Among motorists, constant comparisons are made, whose engine is cooler. And the very first thing that draws attention is horsepower. How they are calculated is separate review.

The next parameter by which the comparison is made is the "gluttony" of the car, how quickly it accelerates, and to what speed. But few people pay attention to the torque. And in vain. Why? Let's figure it out.

What is the torque?

Torque refers to the traction characteristics of a vehicle. This parameter can tell more than horsepower. There are two torque parameters:

  • On the wheels of a car - the force that sets the car in motion;
  • In the engine, the force that is exerted from the burnt air-fuel mixture to the piston, and from it through the connecting rod to the crankshaft crank. This parameter shows what potential the power unit has.
What is torque and why is torque more important than horsepower?

The torque that drives the wheels is not equal to the torque generated in the engine. So, this parameter is influenced not only by the pressure on the piston in the cylinder, but also by the speed of rotation of the crankshaft, the gear ratio in the transmission, the size of the main gear, the size of the wheels, etc.

The engine power, which is indicated in the technical literature of each model, is the value of the moment supplied to the wheels. Whereas torque is the effort applied to the lever (crankshaft crank).

Engine torque is measured in Newton meters and indicates the force of rotation of the crankshaft. This unit indicates how much resistance to crankshaft revolutions the unit will be able to overcome.

What is torque and why is torque more important than horsepower?

For example, a car can be powerful (wheel rotation force), but this figure will be achieved only at higher rpm, since the force acting on the cranks is small. In order for a car with such an engine to be able to carry loads or pull a heavy trailer, the driver needs to bring the engine to a higher rev range. But when accelerating, a high-speed motor is useful.

However, there are cars, the transmission ratio of which does not allow them to move at high speeds, but the thrust in them has a maximum indicator already at low revs. Such a motor will be installed in trucks and full-fledged SUVs.

At low speeds, say, off-road, the driver may not worry that his car will stall if he does not turn the engine to maximum rpm in first gear. Engine displacement does not always affect torque. Let's look at a small example. Let's compare the performance of two engines with the same displacement:

Engine brand -BMW 535BMW 530d
Volume:3,0 l.3,0 l.
Maximum power at crankshaft rpm:306 hp is achieved in the range from 5,8-6,0 thousand rpm.258 h.p. already available on 4 thousand
Torque limit400Nm. in the range between 1200-5000 rpm.560Nm. Between 1500 and 3000 rpm.

So, measuring these indicators will help the motorist decide which power unit should be installed in his car, depending on the operating conditions. The 535i model will be faster, so on the track, a car with such a power unit will reach speeds higher than the 530d. No matter how the driver spins the second motor, its speed will not be higher than that of the first analogue.

What is torque and why is torque more important than horsepower?

However, off-road, when driving uphill, transporting loads, the load from additional weight or resistance to crankshaft rotation will force the owner of the first ICE to increase the crankshaft revolution. If the unit operates in this mode for a long time, it will overheat faster.

Another parameter that depends on the amount of torque is the elasticity of the motor. The higher this value, the smoother the unit will work, and during acceleration it will not have jerks, since the torque shelf is much lower. When, in an analogue with a smaller engine, the driver spins the crankshaft, he needs to keep a certain number of revolutions for smoothness. The indicator should be as close as possible to the peak torque when the next gear is engaged. Otherwise, there will be a loss of speed.


Why does a car need torque

So, we figured out the terminology and comparisons. High torque is very important for commercial vehicles because they often have to carry heavy loads, which creates additional resistance to crankshaft rotation.

What is torque and why is torque more important than horsepower?

However, for light transport, this indicator is no less important. Here's one example. The car is parked at a traffic light. Its engine is weak - the average torque of the internal combustion engine is achieved only at 3-4 thousand revolutions. The car stands downhill on the handbrake. To prevent the car from stalling, the driver needs to spin the engine a little harder than if it were on a flat road. Then he smoothly releases the clutch and at the same time the handbrake.

The car stalled because the motorist was not yet accustomed to the characteristics of his car. But in most cases, drivers cope with this situation - they simply spin the internal combustion engine more strongly. And what will happen to the motor if there are a lot of such slides with traffic lights in the city? Then overheating is ensured.

What is torque and why is torque more important than horsepower?

To summarize:

  • Maximum torque at minimum rpm - the ability of the machine to start very easily, carry loads, but the maximum speed will suffer. That being said, the power to the wheels may not be as important. Take, for example, the VAZ 2108 with its 54 horsepower and the T25 tractor (for 25 horses). Although the second type of transport has less power, you cannot pull the plow on a Lada;
  • Torque shelf at medium and high rpm - the ability of the car to accelerate quickly and have a high peak speed.

The role of power in torque

Don't think that torque is now the most important parameter. It all depends on what the motorist expects from his iron horse. These indicators will help the future vehicle owner determine how the car will behave in different road conditions.

In short, torque shows how efficiently the motor works, and power will be the result of this work in practice.

What is torque and why is torque more important than horsepower?

Let's compare a racing car to a pickup truck. For a sports car, the power indicator is important - how torque is processed by the gearbox. Thanks to the high power (implementation on wheels), this car will be able to accelerate quickly and reach higher speeds at peak. In this case, the motors are able to spin up very strongly - up to 8 thousand or more.

A pickup truck, on the contrary, does not need high speed, so the gearbox is designed so that the torque from the engine is distributed to increase traction characteristics.

How to increase the torque?

This work cannot be performed without intervention in the design of the power unit. However, there are more expensive and budgetary methods. In the first case, the increase in the indicator will be noticeable. However, the minus of this tuning is that the engine's working life is significantly reduced. Repair of the forced unit will also cost more, its "gluttony" will also increase.

Here are the costly upgrade options available for a conventional motor:

  • Installation of pressurization for naturally aspirated engine. It can be a turbine or compressor. With this boost, both power and torque values ​​increase. This work will require decent investments for the purchase of additional equipment, payment for the work of specialists (if the owner of the car is darkness in terms of the arrangement of mechanical means and their work, then it is better to entrust the procedure to professionals);
  • Installing a different engine model. Before deciding on such a modernization of your car, it is necessary to carry out a lot of calculations on the selection of the unit suitable for a particular car. Often, in addition to installing a new motor, it will be necessary to change the location of the additional equipment. If the electronic system is controlled by a control unit, then it will also need to be replaced and adjusted to the operation of existing equipment. And this is just the tip of the iceberg;What is torque and why is torque more important than horsepower?
  • Forcing the motor. The revision allows you to change the design and structure of the power unit. For example, you can increase its volume, install a different camshaft and crankshaft, different pistons and connecting rods. It all depends on how much the car owner is willing to pay for the work of the craftsmen. As in the previous case, before upgrading, you will have to spend money on calculating the expected parameters and whether the installation of specific elements can correct the situation.

If it is not possible to allocate large funds for the preparatory process and repairs, but there is a huge need to increase the torque, then there are cheaper ways.

For example, a car owner can make the following changes:

  • Chip tuning. About what it is and what this modernization has advantages and disadvantages, told separately... In short, professionals interfere with the control unit software, change its settings, including fuel consumption and crankshaft speed;What is torque and why is torque more important than horsepower?
  • Intake manifold modernization. In this case, the system is either replaced with another, more efficient one, or a filter with zero resistance is installed. The first method increases the incoming air flow, and the second reduces the resistance of the next portion supply. It is worth considering that such a refinement requires accurate knowledge and calculations. Otherwise, you can damage the internal combustion engine altogether;
  • Modernization of the exhaust system. As in the previous method, good knowledge of the operation of the exhaust system is required. In a standard car, elements are installed that prevent the free exhaust of the exhaust. This is done for the sake of environmental standards, as well as to reduce noise during operation of the unit, but it makes it difficult to "exhale" the motor. Some motorists, instead of the standard system, mount a sports analogue.

In order for the internal combustion engine to use its potential the way the manufacturer intended, it is recommended to use high-quality consumables. For example, instead of standard candles, you can use more efficient analogs. More details about the varieties and their features are described here... However, the use of high-quality consumables only gives the engine efficiency in accordance with the development of the manufacturer.

And finally, a video about what power and torque are:

Power or torque - which is more important?


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