What is engine braking and why should it matter to you?

Of course, as every driver is aware of, the braking system in your car or van is responsible for slowing it down while driving. While we're familiar with the traditional process of stepping on the pedal to help us brake, you might begin to notice some wear and tear on the system, and it can even lead to more serious damage further down the line. But not everyone knows that using the 'engine brake' method effectively can help improve a vehicle’s overall efficiency.

How your brakes work

Before we get to engine braking, let’s start with the traditional braking system, that you might be familiar with, but not totally aware of how it works. Your brake system is made up of several different components that will work together to make a vehicle stop or slow down when a car is travelling at speed. The vehicle braking system includes master cylinder, servo, brake calipers, brake fluid, brake pipes, brake cylinders, discs, drums, pads and shoes. These components are all linked by the brake hoses and pipes. When you push down on the brake pedal, the servo boosts the force applied to the master cylinder, which fills with brake fluid. The cylinder is then pressurised by a series of pipes and hoses that activate the pistons in the brake caliper. This forces friction from the pads or shoes onto the brake disc or brake drums, which then stops your car.

What is engine braking?

Engine braking is different from the vehicle braking system. When you take your foot off the accelerator pedal and the car begins to slow down, even without touching the brake, this is classed as engine braking. However, engine braking won’t bring you to a complete stop. You’ll still need to use the clutch and brake to fully stop the vehicle.

How does engine braking work?

To use the engine braking method, you will need to make sure your car is in gear and the clutch is not engaged. When you take your foot off the accelerator pedal, the air intake valve is closed and a vacuum is created which restricts air flow to the cylinders. By restricting airflow through this vacuum, resistance is created towards the pistons and this, in turn, slows down the engine. Engine braking is more commonly used on vehicles with a manual transmission. However, it can depend on the transmission of a vehicle. To use engine braking and notice a gradual slowdown in speed of the vehicle, the driver will need to take their foot off the accelerator and shift into a lower gear before gently releasing the clutch.

How can you use your vehicle's engine to control your speed?

To effectively perform engine braking, the driver will need to let the vehicle slow down in speed and shift down one gear at a time. Ultimately, the vehicle will begin to slow down and the driver will not need to use their brakes. The driver can then stop their car safely using the clutch and brake and help minimise the amount of wear and tear on the brakes. A person’s knowledge of their car’s gears and rev ranges will also help them to perform engine braking and they can use this technique to stop their vehicle safely and effectively.

How can you use your engine as a brake?

If a car’s manual brakes fail, engine braking can be used as an alternative. In this instance, drivers should do their best to remain calm, keep their foot off the clutch and carry out the engine braking technique. Another scenario where engine braking can be effective is while driving in icy conditions. >Using your brakes in icy conditions can slow the wheels of the car and increase the chances of skidding on the road. Alternatively, engine braking can create a more controlled way of stopping a vehicle.

When will you feel the effects of engine braking?

Engine braking should be performed while the vehicle is travelling at speed, so the car has some momentum before it eventually slows down. To reap the benefits of engine braking, it’s important that the vehicle is in a low gear to help it slow down as you let your foot off the accelerator pedal. For example, a driver should shift to a lower gear before going down a mountain or a hill. When driving downhill, engine braking can be very helpful. As you begin to go downhill, staying in a lower gear allows you to maintain a steady safe speed.

Is engine braking bad for my engine?

Engine braking, or downshifting, shouldn’t affect your engine or transmission if it is done properly and safely.This technique does generate some heat; however, it is minor and will not have any negative effects on the vehicle.

Should I always use engine braking?

Your vehicle’s braking system, such as the calliper brakes and drum brakes, works by the by using friction. With this in mind, it can ultimately lead to wear and tear on your braking components compared to when engine braking is used. However, please remember that this does not mean that you should always rely on engine braking. A mix of engine braking and traditional braking is recommended as the best course of action.

When should you not use engine braking?

It can be potentially dangerous to shift up in gears and increase speed without engaging the accelerator. It’s also important to remember that you don’t have brake lights when engine braking. Of course, this shouldn’t be too much of a concern, as you’ll be slowing down gradually anyway. However, this is why you shouldn’t use first gear to engine brake from high speeds as you’ll begin to stop quickly and give no warning to other drivers, while putting an additional strain on your gears and synchromesh.

Why could it be dangerous to keep the clutch down?

It’s worth bearing in mind that engine braking might unnecessarily take your focus away from the steering wheel and road ahead as you use your hand to change gears and keep your foot on the clutch.

Getting your brakes checked over with Arnold Clark

Any issues or problems to a vehicle’s braking system can potentially cause serious safety issues. If you notice any of signs that your braking system is not working properly, you should take your car to your local service centre where a fully trained and qualified technician will be able to investigate and quote you for the best fix or replacement of the correct failed parts.