Does Changing Muffler Affect Fuel Consumption? (Tested)

By December 11, 2022Muffler, Uncategorized

Changing the muffler on your vehicle will affect its fuel consumption. If you get an aftermarket muffler that provides less restriction to the gas flow in the exhaust system, you could achieve better gas mileage. 

If you get a more restrictive muffler like the regular mufflers, do not expect an improvement in the fuel consumption of your vehicle. 

Personally, I have tried using a straight-through muffler in place of my stock muffler. It did improve the sound significantly and horsepower a little bit. I also did notice a slight improvement in the fuel consumption of my car.

What’s Muffler & How Does It Work?

Image of the internals of a muffler

Muffler has chambers that will bounce sound waves to each other to cancel out.

A muffler can be seen as a part of the exhaust system, which you can find at the end bottom of the vehicle. The major role of the muffler is to dampen exhaust emissions and reduce engine sound. 

The muffler is made of steel and has an aluminum coating that provides a shield against heat and dangerous chemicals from the exhaust system. The exhaust and engine system can create a lot of noise. The muffler’s job is to ensure that the engine and exhaust system noise are reduced drastically while also providing cleaner exhaust gas for the environment. 

Before understanding how the muffler can reduce the sound, you need to understand how the sound is created. When the engine releases exhaust gasses, they come with many sound waves caused by vibration caused by the rushing gas colliding with the exhaust parts, even itself, and other lower molecules. This collision creates an enormous amount of sound.

The muffler solves the sound created by the rushing gasses by tackling the vibrations. An exact opposite sound wave must be created to cancel out the sound, which will cancel out the vibration caused by the gasses. When a high-level sound wave meets with something opposite, a low-pressure sound wave, they automatically cancel their sound, causing no sound. 

The muffler is designed to create an opposite sound wave to counter the exhaust gasses. It has a less complicated design with perforated tubes that can direct sound through the holes and out another direction and into the resonator going back to the front of the muffler. 

Through the process, some sounds pass through the holes to the resonator while others reflect through the chamber wall. The resonator is designed to have a length that allows the sound to hit the wall and move through the holes it came from, where it will meet another sound wave. 

In this case, the high-pressure sound wave that moves through the resonator will meet with the low-pressure sound wave reflected from the center of the chamber. When these two sound wave pressures meet in one place, they automatically cancel each other. 

Also Read: Do Mufflers Increase Horsepower: An Expert Weighs In

Will a Different Muffler Change Fuel Consumption? 

Glasspack mufflers

Straight through (Glasspack) muffler doesn’t have chambers and will allow exhaust gasses to exit easily.

Using a different muffler will affect the fuel consumption of your vehicle. Changing to an aftermarket high-performing muffler will give your vehicle even better fuel consumption because of its nonrestrictive design, allowing it to release more exhaust gasses. It will enable the engine to breathe better.   

By getting a good aftermarket muffler, your vehicle can dispose of waste gasses faster; while doing so, back pressure falls dramatically in the engine. Once this happens, you should get better gas consumption and improved horsepower. 

When there is too much back pressure, there is an increase in the mechanical workload on the engine. It allows the engine to do more work to create the same amount of power needed for use. If there is an increased workload on the engine, the engine will also require more fuel to cope with the power requirement.

However, when the workload is reduced on the engine by reducing the back pressure, the engine requires less fuel to create a specific amount of power to move the vehicle. 

It is also important to know that there is a minimum amount of backpressure that a vehicle is required to have. Freeing up your vehicle exhaust system too much and releasing all the back pressure may affect the RPM of your vehicle. The goal is to find a muffler that frees up back pressure but not too much. 

Mufflers can affect the level of fuel consumption on your vehicle when changed. Depending on the aftermarket muffler that you get will show the quality of improvement of your vehicle gas consumption. Some aftermarket mufflers are designed to give your vehicle better airflow. Once the muffler can take in larger exhaust gasses and exit them faster, the engine can breathe better.  

Also Read: Glasspack Mufflers 101: Sound, Power Gain & Are They Legal?

Type Of Mufflers That Reduce Fuel Consumption

Mufflers play a huge role in a vehicle’s fuel consumption and can do this by improving airflow. To achieve better fuel consumption, you need the right type of muffler, and high-performing mufflers are the types that can achieve better gas mileage for your vehicle. 

There are three major types of high-performing mufflers in the market today that could reduce (improve) your fuel consumption, including the following.

1. Straight Through Muffler 

the internal of performance muffler

The straight-through provides a design that allows the gasses to escape the exhaust system faster. As the name implies, it uses a straight pipe with a perforated tube to silence the gasses while sending more gasses away from the exhaust system. It frees up the back pressure and allows the engine to utilize the air-fuel mixture efficiently, reducing fuel consumption. .   

2. Chambered Muffler 

Image of the internals of a muffler

The chambered mufflers make use of a series of walls and baffles. What they do is that it reflects exhaust gasses into various chambers. It allows the exhaust gasses to bounce through the chambers while exiting the exhaust system fast. Its nonrestrictive nature also allows faster gas flow and reduces the backpressure. Once there is a reduction in the backpressure, there will be better fuel consumption. 

3. Dual Mufflers

Having a dual muffler means having a dual exhaust system, which is one of the best ways to release gasses faster and reduce the fuel consumption of your vehicle. The gasses pass through two separate exhaust systems and drastically drop back pressure. Once the exhaust gasses are exiting faster, the engine can breathe better and achieve a better air-fuel mixture reducing fuel consumption. 

4. Turbo Muffler 

Turbo mufflers

The turbo muffler uses an s-shape designed tube that helps reduce the noise created by the exhaust gasses. The problem with this muffler is that it may be less nonrestrictive than those mentioned above. It will provide better fuel consumption than a regular muffler because it can free up exhaust gasses better.  

Also Read: 5 Muffler Types Compared For Sound, Power & Mileage (Detailed)

Type Of Mufflers That Increase Fuel Consumption

Regular stock mufflers typically provide a level of restriction, which may not be able to provide as much fuel economy as the aftermarket high-performance muffler. 

Standard mufflers slow the movement of the gasses so that noise-canceling can occur. The process provides lesser gas flow and can equally increase fuel consumption. 

In general, mufflers are not meant to increase the fuel consumption on your vehicle. They are designed to improve the quality of your vehicle’s sound and emission. When buying a muffler, some may reduce the level of fuel consumption than other types of exhaust. 

You can not compare the original mufflers that come with your vehicle to perform as much as high-performance exhaust. High-performance exhausts are designed to give your vehicle increased power by increasing airflow. 

Does Louder Muffler Impact Fuel Consumption? 

As a general rule, louder mufflers will reduce fuel consumption because they are designed in a non-restrictive way. When a muffler is non-restrictive, your fuel consumption will improve.

On the other hand, the more restrictive the muffler gets, the lower the chances of its performance in gas mileage compared to a non-restrictive one. 

If your exhaust or muffler becomes louder and you discover a change in the fuel consumption level, there could be a leak in your exhaust system. When there is a leak in the exhaust system or muffler, the exhaust becomes louder. It also might affect the level of fuel consumption of the engine depending on where the leak is coming from. 

Also Read: Are Bigger Exhaust Pipes Louder?

Does Removing Muffler Impact Fuel Consumption?

Cutting the muffler on your vehicle could affect the fuel economy of the vehicle. Depending on where you cut the pipe, removing the muffler could either improve fuel economy or worsen it.

When you cut the muffler, it will significantly improve airflow. Once the muffler is gone, the restriction caused by the muffler is removed, and back pressure is reduced. You will experience an improvement in fuel economy, but the improvement might not be as significant as you would expect.

It is important to note that the muffler delete should be done well and ensure that it does not affect other parts of the exhaust. If the process affects the O2 sensor, it will affect the vehicle’s fuel economy. 

If the O2 sensor is damaged, it will give an off reading to the engine’s computer system. The off reading may affect the air-fuel ratio and increase the fuel sent into the combustion chamber, which leads to an increase in fuel consumption.

That said, remember, removing the muffler will make your vehicle extremely loud because the only mechanism set in place to reduce the sound of the engine has been removed. 

Also Read:


Mufflers play a significant role in noise cancellation in a vehicle. The restriction of the muffler helps create better noise cancellation and makes your vehicle move more quietly. You need a less restrictive muffler if you want better power and louder sound. 

A less restrictive muffler also gives your vehicle better gas mileage. The muffler can reduce back pressure to the minimum, and the engine will breathe well, giving better engine performance and less fuel consumption. 

Ifandi L.

Ifandi L.

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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