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Exhaust braking is an impressive engineering phenomenon that makes modern diesel engines that much more functional. Would you like to know if exhaust brakes are hard on an engine? Well, we have researched this topic and have answers for you.
Exhaust braking is not hard on your engine. Some Dodge truck models before 2006 had reverse-thrust bearing problems due to exhaust brakes—but starting in 2006, Dodge built engines compatible with exhaust brakes.
In this article, we’ll compare exhaust brakes to engine brakes, and we’ll determine whether exhaust brakes use more fuel. We’ll also discuss how effective exhaust brakes are and how to best use them. Finally, we will discuss how an exhaust brake works on a 6.6 Duramax and if engine braking is the same as downshifting. Keep reading to learn more.
Are Exhaust Brakes Hard On Engines?
Exhaust brakes are not hard on engines. They will cause no issues with continual use. Some people fear this braking system might cause issues because when braking, the exhaust is blocked, and the pressure in your engine can build to 60 PSI.
While this is a lot, engine component metals are capable of withstanding this stress without issue.
There were some problems with the reverse thrust causing bearing problems on Dodge trucks before 2006, but since then, they have improved their engine design to specifically allow exhaust brakes.
A post-2006 Dodge truck will have no problems or experience extra wear from making use of exhaust brakes.
Does An Exhaust Brake Use More Fuel?
Using an exhaust brake does not directly use more fuel, but it does indirectly. When you use an exhaust brake, the exhaust is blocked and builds up in the engine. This slows the vehicle but also cools the glow plugs in a diesel engine.
When the plugs cool down, they do not burn fuel as efficiently. This does cause a mild decrease in fuel efficiency. So while braking itself doesn’t use more fuel, using exhaust brakes does cause you to use more fuel overall.
What Is The Difference Between An Engine Brake And An Exhaust Brake?
Engine brakes and exhaust brakes work in very similar ways. They both increase the pressure in the engine, making it harder for the pistons to move and thus slowing the vehicle. They also have some key differences.
Engine brakes increase pressure in the engine by using compressed air. There are two drawbacks to this method.
First, compressed air can run out. Have you ever seen those run-away truck roads? They are to catch a truck that has no way to slow down while going down a sloped road. Most times, trucks need to use them because they run out of compressed air for their engine brakes.
The other big drawback to engine brakes is that they are loud. Have you ever seen one of those engine brakes restricted signs? That is because people do not like the sound engine brakes make, so they try to restrict them in residential areas.
Engine brakes are more powerful than exhaust brakes. They have better stopping power, which can be useful when driving down steep mountain roads.
Exhaust brakes increase pressure in the engine by blocking exhaust gasses and allowing pressure to build.
The method that exhaust brakes use is silent, unlike engine brakes. This means they can be used in populated areas. They also don’t run out of air, which can be good when traveling on dangerous mountain roads.
The one drawback is that they are not as powerful as engine brakes.
So as you can see, while both increase pressure in the engine, one with blocked exhaust and one with compressed air, they have different advantages and disadvantages that need to be considered depending on your specific needs and preferences.
How Effective Are Exhaust Brakes?
So while exhaust brakes are not as powerful as engine brakes, they are quite effective. They are capable of slowing a large truck to a stop going downhill without even using its conventional brakes.
How effective brakes are is measured in units of power. Exhaust brakes’ braking effectiveness is 60%-80% of the engine’s maximum power output.
So while engine brakes may have a slight edge on stopping power, you can be confident that exhaust brakes will be an effective braking solution.
Should I Drive With The Exhaust Brake On?
It is recommended to drive with the exhaust brake on. Driving with it on will in no way cause damage to your vehicle. It will also reduce soot from getting into the turbo and preserve the life of your other brakes.
So when it comes to driving with the exhaust brake on, you can know that it is safe and beneficial to do so.
How Does An Exhaust Brake Work On 6.6 Duramax?
On a 6.6 Duramax, an exhaust brake works by forcing the engine to pump against the exhaust’s backpressure. This is done by adding a butterfly valve in the exhaust just after the turbo.
When you turn on the exhaust brake, a solenoid or a pneumatic actuator is used to close the exhaust brake valve and allow pressure to build in the engine, helping to slow the vehicle.
Now, most exhaust brakes work with a simple on-off switch. This means that the exhaust brake in this situation is an all-or-nothing brake system.
Another exhaust brake design utilizes a Computerized Brake Controller or CBC to add some features like allowing you to partially engage the brake to help slow you down without cooling off your glow plugs much. This design increases fuel efficiency if used properly.
Some designs of exhaust brakes have safeguards to prevent any conflicts with the vehicle’s exhaust system, valvetrain, transmission, or cruise control. Some exhaust brakes have some downsides as well.
When the exhaust brake is off, it should allow full airflow through the exhaust. Some cheaper exhaust brakes can reduce airflow even when in the off position, reducing gas efficiency.
It can be important when installing an exhaust brake that you use a reliable high-quality design over a cheap design.
Is Engine Braking The Same As Downshifting?
Engine braking is not the same as downshifting. They both help to slow your vehicle but through very different methods.
Engine braking uses compressed air to increase pressure in the engine, making the engine work against that pressure. This helps to slow the vehicle.
Engine braking is also very loud. The sound that a vehicle makes when using engine brakes is well known and is why it is banned in residential areas.
Also, engine braking is finite. You can not use your engine braking indefinitely without it running out. Once your vehicle is out of compressed air, you will have to wait for more to build up. This can be an issue if you are going down a long mountain road with many turns.
These traits of engine braking are quite different from downshifting.
Downshifting is another method that you can use to slow a vehicle. In the downshifting method, you lower the vehicle’s gear to change the gear ratio.
This causes the engine to have to rotate the gears more to cover the same distance. This increased mechanical movement drains energy from the engine, slowing the vehicle.
Unlike the loud noise made from engine brakes, downshifting does not make a loud noise.
The engine revving sound may change to a more high pitch noise since the gears are rotating faster, but it doesn’t make a loud irritable noise. For this reason, downshifting is not banned in residential areas.
Also, you can’t run out of downshifting like you can with compressed air in engine braking. You can shift down a gear as often as you want without worrying about running out of time doing so.
Downshifting can be a little hard on your transmission, which is why drivers typically use a combination of downshifting, engine braking, or other forms of braking.
By combining different forms of braking you can extend the life of not only your brakes but also your vehicle.
In sum, exhaust brakes are not hard on your engine. It can be important to use exhaust brakes in certain situations to help extend the life of your other brakes. Also, if your engine brakes run out of air, it can be critical that you have a backup method to slow your vehicle.
Different brakes have advantages and disadvantages, and knowing how they work can help you to use the right brakes at the right times.
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