Engine Brake 101: How To, Clutch Wear, Fuel Usage & Legality

By February 13, 2022Brakes

Engine braking helps in slowing the car by releasing the accelerator pedal and not using the regular foot brakes.

We all use engine braking on some level, whether we realize it or not; when you’re driving down a hill, and you downshift to get to a controlled stop quickly, you’re using engine braking.

My initial impression to engine braking was not a good one (probably like yours). I was thinking of questions like Won’t it hurt the engine? Is this even legal?

Turns out, engine braking is actually quite good and much more efficient than regular brakes.

Let’s discuss this further. I will cover everything you want to know about engine brakes in this article. 

What is Engine Braking?

Engine braking is the act of slowing down a vehicle by releasing the accelerator and shifting down through gears rather than engaging the footbrake.

In technical terms, it uses decelerative forces in the engine to lower the speed at which the wheels move. This occurs when the accelerator pedal is depressed, causing the air intake valve to close and creating a vacuum. It limits air passage to the cylinders, sapping energy and generating a braking force that brings the car to a halt.

So, using engine braking to minimize brake fade or failure is a really clever strategy. Most truck drivers are trained to use engine braking extensively in their daily driving since it is a practical strategy to save fuel and prevent brake problems on their trucks.

How does Engine Brake Work?

Engine braking is only effective when the vehicle is in gear. When the clutch is released, the braking force generated by releasing the accelerator is not transmitted to the drivetrain. So the wheels continue to move at the same pace. 

You may accelerate engine braking by shifting down into a lower gear. The higher the RPM, the more torque is sent through the transmission, allowing the car to quickly reach a controlled stop.

anatomy of combustion chamber

During engine brake, the air intake is closed – causing a lack of air and thus, vacuum. This vacuum will prevent the piston from moving down – which causes engine brake.

How Do You Use an Engine Brake?

To perform engine braking, take your foot off the pedal and change into a lower gear before carefully releasing the clutch. Allow the car to slow to a safe speed before shifting down one gear at a time.

This will begin to slow down the vehicle and allow you to avoid needing to apply the brakes. Then, using the clutch and brake, you may safely stop the automobile, reducing wear.

Engine braking is the finest option when gravity increases the car’s speed and demands more energy to stop your vehicle. Using engine braking in these instances will help reduce brake fade and, as a result, keep you and your surroundings safer.

On the other hand, engine braking is not a replacement for regular brakes. It makes no sense to stop or slow down with the engine if you need to halt or slow down rapidly.

Here’s an article that talks more detail about engine brake and downshifting. They both closely work with each other and you need to master both. It’s for motorcycle but the concept is exactly the same.

Related Article: Should You Downshift When Stopping On A Motorcycle? 

Does engine braking use more fuel?

Engine braking does not use more fuel than traditional braking. There should be no impact on fuel consumption. 

Even if there is, this should be an insignificant amount that you won’t tell the difference. Personally I have been using both engine braking and regular brakes regularly and I don’t notice any dip in fuel consumption.

Is Engine Braking Legal?

Engine braking on regular vehicles is legal because it doesn’t create any loud noises or create harmful pollution.

In some states of the USA, engine braking is prohibited, mainly in residential areas.

However, this applies only to trucks with powerful diesel engines using “Jake brake,”  because it causes loud noise comparable to firing a gun. For example, California and Illinois.

Related article: Exhaust Vs Jake Brake: Loudness, Engine Damage, Pros & Cons

The noise level range of a properly muffled engine brake is 80 to 83 dB(A), which is comparable to a household garbage disposal, food blender, or a diesel vehicle going at 40 mph (64.4 kph) and is 50 feet away.

Does engine braking wear the clutch?

Engine braking does not cause clutch wear. Many people still assume that this produces excessive wear on the gearbox, clutch, or engine; however, this is incorrect. You’re safe as long as you’re not riding the clutch, rev-matching while changing gears, and not over-revving the engine.

A sudden downshift might harm your clutch plate and transmission system if you’re traveling at high speed. You must understand how to do it correctly. If you perform engine braking incorrectly, you risk damaging your transmission system and clutch plate.

Engine braking is helpful if done correctly and handled effectively. It can benefit in terms of greater safety when driving.

Do automatic cars have engine braking?

Some automatic cars can perform engine braking. However, most automatic transmissions are not often programmed for frequent manual shifting; this is why they respond poorly to engine braking.

Engine braking with an automatic transmission is often less effective than engine braking with a manual transmission. It will overheat if controlled in the same manner as a manual transmission.

The ability to use engine brake in an automatic transmission is dependent on the availability of a user-initiated downshift. Some automatic transmissions do not allow the operator to downshift manually. However, caution should be exercised to ensure that engine braking is not used excessively.

Also, downshifting an automatic transmission while driving downhill is not a good idea. High temperatures will quickly kill an automatic transmission, so keep an eye on this.

Is Engine Braking Better than Normal Braking?

There are times when using the engine brake is a safer and better alternative to using the footbrake.

Which muffler is your car right now?

It will help to slow the car down without the risk of skidding or heating the brake pads to the point where they no longer work.

Using the footbrake to slow the car down is almost always the safest and quickest technique under typical driving conditions. You can utilize the engine brake just to prevent brake wear rather than as a safety measure in normal driving situations.

 

Engine braking is better than regular foot brakes in these instances:

1. When Driving Downhill

Engine braking can be a lifesaver in this case, which is why you’ll constantly see warnings at the top of a steep hill instructing you to shift into a low gear

Third or even second gear will help the car maintain a constant pace and allow you to barely touch the brakes to moderate your descent, ensuring that they are not subjected to excessive wear.

It’s important not to misuse the brakes when driving downhill for extended periods. As the car acquires momentum due to gravity, more braking is required to slow it down, which means the brakes might begin to ‘fade’ due to overheating and reduced friction, which is the last thing you want while driving down a steep hill. This is why engine braking is a better alternative.

 

2. When Driving in Snow and Ice

Using engine braking in this situation is a better option because using the footbrake will actually make matters worse when roads are slippery. When the wheels lock up or are slowed unexpectedly, the car will easily enter a slide.

Driving in snow and ice may be challenging. We all instinctively want to apply the brake pedal when we feel we’re losing control of the vehicle in these unsafe conditions. 

In snowy weather, the problem is that you must strike a balance between being in a high enough gear to prevent wheelspin and remembering to drop down ratios early enough to keep the wheels rolling rather than coming to a complete stop.

You should also maintain a safe distance from the vehicle in front of you and anticipate potential hazards so that you can downshift and utilize engine braking to slow the vehicle rather than relying on the foot brake.

Pros of Engine Braking

1. Engine Braking reduces wear

Engine braking reduces wear on your break pads because you are effectively slowing down the vehicle without using brakes.

This reduces wear, heat, and fading of your brake pads.

 

2. Engine Braking is safer

By engine braking, when you observe traffic slowing ahead of you rather than waiting until the last second to stop, you allow yourself and people behind you more time to respond to changing situations.

It is important to regulate speed while driving down very steep and long slopes; active engine braking (shifting down in a lower gear) is useful in such circumstances.

You may keep safe intervals by just letting off the accelerator rather than hitting the brakes. Remember that a brake light serves as a warning to the person behind you, forcing them to brake, then the person behind them to brake, and so on.

You will also be better positioned to respond if something unexpected occurs. A lower gear allows you to either slow down or accelerate to dodge an impending threat.

At low speeds, a high gear saps power and increases the likelihood of a stall. Also, sudden, sharp braking increases the possibility that the automobile behind you will drive into the rear of you.

      

 3. Engine Braking does not cause engine damage

Engine braking won’t cause engine damage because the engine was built to be driven in this manner. Engines are built to spin at thousands of rpm for hours on end. While changing down can be a little rough at times, it does not cause any harm.

In contrast to braking or shifting into neutral, engine braking reduces fuel consumption. You’ll also use less fuel when pushing away in a lower gear than when pulling away in a high gear at low speeds. All of this adds up to more secure, cost-effective drive-on brakes that will last longer.

It is preferable for an engine to progressively shift down (or up) through gears rather than shifting from 5th to 2nd.

 

4. Engine Braking provides better vehicle control 

While your primary braking system’s braking force can be erratic, the engine braking effect is much smoother, giving you superior control over your vehicle or truck. This better braking control comes in handy when driving in ice or wet weather.

Cons Of Engine Braking

1. Engine Braking means no brake lights

Engine braking does not cause the brake lights to illuminate. It means that the drivers behind you may not detect your vehicle slowing down.

So, if you’re utilizing the engine brake at night, it’s a good idea to press down on the brake pedal every now and again. This causes your brake light to illuminate, alerting the driver behind you that you’re slowing down.

 

2. Engine Braking triggers high RPMs

Your engine’s RPM may increase when you downshift to improve engine braking. Also, operating your car at high RPMs for extended periods can cause the engine to overheat, putting a strain on your cooling system and radiator.

However, as long as your RPM remains well below the redline, your engine should be fine.

 

3. Engine braking causes stress on transmission

Downshifting rapidly during engine braking can put a lot of strain on your manual transmission system’s gears and clutch plate.

If this stress is too great, your transmission system and clutch plate may suffer damage. Furthermore, the expense of repairing your transmission system may outweigh any savings from extending the life of your braking components.

A good rev-match while downshifting will counteract this.

 

4. Engine Brakes may produce noise

Engine brakes like Jake Brakes may produce loud noise when applied. This doesn’t apply to regular vehicle’s engine brakes though.

If you are driving a truck with jake brake, then this will be a problem and not to mention illegal because of the sound produced.

If you are driving regular vehicles, engine braking will not produce noise.

Engine braking is restricted in various states in the United States, primarily in residential zones. It applies to trucks equipped with powerful diesel engines. 

Conclusion

Engine braking can be quite useful and effective; it decreases fuel consumption while also preventing fading of your brake pads.

However, as useful as engine braking is, it should not be utilized excessively. When you need to come to an abrupt halt, it is best to utilize the foot brake rather than the engine brake.

Ifandi S.

Ifandi S.

Passionate about everything mechanical. Ifandi has been involved with motorcycles and cars since the old days - in his family's auto parts shop. Want to keep in touch? Scream "STRAIGHT PIPEEEEE" at the top of your lungs and Ifandi will show up.

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