Is it time to change your car's engine? Whether you are looking for a new one or second-hand engines, there will be several figures that appear in the technical specifications.
One of these is known as "torque". Don't know what it is? Allow us to explain its meaning and why it is so important that you know how to interpret the torque of a car's engine.
What is engine torque?
To understand clearly what engine torque is, we are going to explain it with an example. As you well know, power indicates the speed of a car with a specific engine.
If the engine has a lot of power, it goes fast up to the rev limit. Well, what engine torque indicates is the force of the engine, that is, the force it must exert to increase speed.
For example, if a car has low torque, it will accelerate slowly, whereas if it is high, it will only take a few seconds. This measurement is expressed in Newton metres (Nm), although it is sometimes also given in pound-feet (lb-ft).
Why is it so important to check the torque when buying an engine?
As we have explained, the torque tells us the force with which the engine accelerates. Thus, cars with high torque accelerate slowly at first, but faster at low revs in a high gear.
On the other hand, cars with low torque accelerate quickly at first, but more slowly at low revs when driving in a high gear.
Another major difference is gear changing. Engines with low torque are harder to drive, requiring many gear changes and high revs to maintain power. On the other hand, those with high torque are easy to drive and do not need as many gear changes to accelerate.
How does it affect fuel consumption?
The relationship between engine torque and fuel consumption can be complex, but let's look at it with some examples.
Under efficient driving conditions:
· If the engine has good torque at low revs, it allows the vehicle to accelerate and maintain the desired speed without having to keep pressing the accelerator continuously and at lower revs. This means less fuel consumption.
· Fewer gear changes are needed, which helps reduce fuel consumption as the engine works less.
· Ensures relaxed driving, without having to push the car to get the desired response.
In situations of high power demand:
· In cases where the engine's maximum torque is delivered at high revs, the driver will need to accelerate more, revving the engine to obtain the desired power. This will increase fuel consumption.
· In order to achieve the acceleration, or forces needed, in certain situations such as climbing a hill or overtaking, if the engine has low torque you will need to downshift, which will increase the revs and, with it, fuel consumption.
What types of cars have low torque or high engine torque?
In reality, it is quite straightforward to find out — you just need to look at the type of engine:
Car with low torque
As a general rule, these are cars with smaller petrol engines and no turbo, such as city cars or mid-range sports cars.
Car with high torque
Obviously all other vehicles with large engines, whether petrol or diesel. Although there are also cars with very powerful engines, especially turbocharged petrol ones.
Electric cars — what torque do they have?
It is true that the torque of an electric car's engine is not very high. However, as a point in its favour, the engine torque is available instantly.
While internal combustion engines produce maximum torque at certain revs, electric motors do so instantly, allowing the desired speeds to be reached immediately.
Some considerations when assessing engine torque
Now that you are clear on what torque is and what its function is, we are going to give you some tips when you are looking at engines for your car!
· Choose one that offers a driving feel that suits your driving style, such as quick response or power from low revs.
· Has the right capacity to carry passengers.
· If you are towing a trailer, you will need a car with plenty of torque to drive comfortably.
· In terms of power, it should offer the best fuel efficiency in certain situations.
· Matches the main use you will make of your vehicle.