A Blog That Revolves Around Automotive Industry


How can you use your Vehicle’s Engine as a Brake?

Car Engines

All Bout the Term “Engine Braking”

Using the foot brake is the most common and most of the time safest way to reduce the speed of your vehicle. In an emergency situation it is even more critical to reduce the speed suddenly and safely and foot brake works just fine for that purpose. You see a situation where you require your vehicle to slow down within a certain distance and you apply the pressure on the brake paddle accordingly and the vehicle stops within that range.

Interestingly, there is another way to reduce the speed of your vehicle without using the foot brake that is safe and, in some instances, better than the foot brake. Its called engine braking. Let’s have a detailed look at how the engine braking works and what are the advantages and disadvantages of such braking method.

How does engine braking work?

Engine braking works by taking off your foot from the accelerator and shifting down through gears.

Taking your foot off limits the airflow to the car engine which results in decrease of the speed at which the wheels are rotating. When you take the foot off the paddle, the throttle body valve closes down causing a sudden cut of airflow towards the engine and creating a vacuum in the cylinders. Combustion process in the engine is restricted due to the limited airflow and engine drop the power to slow the wheels.

Is it bad to use your engine to brake?

A common concept is that engine braking can damage your engine and engine braking is an unnatural way of decelerating your vehicle. Well, we are happy to report that this is not correct and should be perceived as just a myth.

Engine braking does not harm your engine at all. Engines are designed to run at thousands of revs per minute for hours without break. They are way too strong to sustain damage because of just limiting the airflow into them.

Yes, the engine twitches a bit when you do that but that is absolutely fine. Engine should be able to withstand that without any damage. All you have to care is that not to shift down straight to 2nd form 5th and do it gradually and you are good as gold.

How do you use an engine brake in a manual transmission?

Although it is possible to engine brake in an automatic vehicle as well but engine braking achieves best results when it is used in manual transmission vehicle. You can use the gear to L which stands for Low range gears and drive on slow speeds just make sure never to perform this manoeuvre at high speed. If you have paddle shifters or Tiptronic gear system then just down shift it as you would do with manual shifting.

With a manual engine it is far simpler. All you need to do is take you foot off the paddle and shift down as the vehicle slows gradually. You can achieve severe braking as well but you must know and understand the rev range and gearing of your vehicle.

What happens if you press brake without clutch?

Usually, the rule of thumb is that if you are driving slowly then it makes sense to press the clutch and then brake so you do not stall the vehicle. If you are driving faster then you should press the brake and then clutch as the engine braking comes into play and saves your brakes and fuel as well.

Not pressing the clutch keeps the engine engaged and taking your foot off closes the valve and deprive the engine from the air flow which activates engine braking that is helpful in saving brakes, fuel and engine and make the vehicle more efficient.

Why is engine braking illegal?

Usually, engine braking is fine and acceptable in most areas and vehicles but in some areas, it is prohibited and deemed illegal to engine brake. When the road is going through the residential areas, this is when you see the signs saying no engine braking allowed. Reason is that engine braking especially in commercial and larger vehicles creates considerable noise which is multiplied in the late hours or night times. It causes disruption to the locals and effect their quality of life. Apart from that particular area engine braking is fine everywhere else.

Is it better to downshift or brake?

There is a never-ending debate between the petrol heads that argues which way is better downshifting or braking. Supporters of downshifting argue that you can save on the wear and tear of your brakes and prevent overheating brakes. On the other hand, supporters of the brakes say that you may save some brakes but then you would be spending more on fuel and damage to your engine and transmission.

Our research-based opinion says that downshifting should be applied when you have to use constant braking. For example, if you are going downhill then you may require to slow down the vehicle on a constant basis. Using the brakes only would get the temperature up to dangerous levels. You should on such occasion, apply the downshift braking. Otherwise, you can use the normal braking to keep the car smoother on the tarmac.

What is the difference between an engine brake and an exhaust brake?

We have already established that engine braking is very helpful in controlling the vehicle and it is important to know that while in gasoline vehicles and small semi-trucks you can take advantage of the engine braking, for heavily loaded trucks and Diesel vehicles you may have to use the exhaust brake to enhance the mechanical braking.

A diesel exhaust brake is an intentionally placed controllable physical restriction within the vehicle exhaust system that creates additional exhaust system backpressure, resulting in a reduction in vehicle speed. It is more beneficial in diesel engines as these are regulated by the fuel distribution instead of the air and heavy vehicles use exhaust braking better to regulate the braking system.

Do you have to shift down when braking?

It depends if you have to down shift while braking. If you are employing engine braking by releasing the gas pedal, as a result the car would slow down and when the car slows down, naturally, you would have to shift down to continue the process.

A gradual shift down in the gears is also recommended when you are applying engine braking. It helps taking the load off the mechanical braking system of the vehicle.

How do you slow down a car without stopping?

Its not difficult to slow down a car without stopping all you have to do is apply a set of braking manoeuvres in the right order. First of all, just let go of the accelerator paddle. Let the vehicle slow down as much as possible shift down when you feel it is necessary now, and when the vehicle is about to stop press the clutch and bring the vehicle into natural.

Is it OK to press clutch while braking?

We can only think of two instances when you should apply the clutch. When you are bringing the car to a stop or when you are changing to a lower gear.

Apart from those two situations, avoid pressing the clutch as it is not necessary. When bringing the car to a stop, you should ensure to press the clutch only when the car is about to stop so you do not stall the vehicle and while changing the gear down you should engage the clutch only while changing gears as it is necessary to press the clutch before you downshift.

Can you go from 3rd gear to 1st?

You may do that depending on the speed of the vehicle and the gear ratio you are running in the gearbox settings. If you shift from 3rd to 1st at a bit of a speed then chances are that you would over-rev the engine and cause serious damage to the gearbox. So, it’s not recommended to shift down unless you are in travelling at a speed that is recommended for such gear.

Read More