Why Do Some Cars Have Multiple Exhaust Pipes?

Car with multiple exhaust pipes

Why do some cars have multiple exhaust pipes?

The main reason behind having multiple exhaust pipes in cars is to get the residual air out of the cylinders rapidly so that the next interchange can begin. Having multiple exhausts can help with engine efficiency, capacity and enhance performance of the engine.

Apart from moving burnt air-fuel mixture out of the engine, an exhaust system holds the responsibility of cleaning the emission and reducing unnecessary noise generated in a car. Here are a few more reasons:


Greater Capacity

Multiple exhaust pipes offer a substantial capacity so that the resistance towards the flow of gases is considerably lower than having a single exhaust pipe.


Engine Efficiency

A car engine functions efficiently with the use of multiple pipes. These pipes are connected to independent gas cylinders and pass through them. All of them are of the same length. They are further connected to a single pipe of the same length of tubing, extending till the end to reach the tailpipes.

A similar result can be achieved even in the case of inline engines where the cylinders are placed separately and each pipe connected to it runs the full length reaching the tailpipes.


Performance enhancement

The performance of a car is enhanced manifold if it has separate exhaust systems. The pressure on the back of the car reduces the power of the vehicle. Due to the dormancy of the mass of the exhaust gas, it takes considerable time to pass.

As a result, an improvement in car performance can be achieved with an efficient engine to aid in quickly releasing the gases from the cylinders.


Types of exhaust pipes for cars

The three major types of car exhaust pipe systems are straight, turbo back and cat-back.

  • Straight exhaust pipe
  • Turbo back exhaust pipe
  • Cat back exhaust pipe


Straight Exhaust Pipe

Straight Pipe exhaust systems, as the name suggests, are those which use straight pipes that begin on top, right at the car’s exhaust headers and go up to the back.

The design of these pipes is such that there is no filter between the engine’s sound and the rear of the car. The cost of this pipe would go up to $1,000.


Pros of a straight exhaust pipe

Enhanced Aesthetics

This system provides a sporty and more aesthetic appeal to a car. The look of the car is more attractive when the pipe plunges out of the rear side of the car.


High Performance

A straight pipe exhaust system offers better performance when compared to the standard exhaust system. Such pipes are mostly found in racing cars. The pressure of the exhaust gases is much lesser on the engine in such systems thereby resulting in better performance.


Greater Fuel Economy

Many car owners are astonished to notice the increase in their fuel economy after fixing a straight pipe exhaust system. The structure of the pipe is a major contributor to this as it helps in expelling the gases from the car in a much efficient manner.


Cons of a straight exhaust pipe

Excessive Noise

The excessive noise made by a car due to the straight pipe exhaust system is an off-putting factor. It may be nice at times to hear the noise as it clearly indicates more power, yet continuous exposure to such a high level of sound is certainly not a plus point.


Soaring Emission Levels

This kind of exhaust system does not lower the emission levels due to the absence of a catalytic converter. This converter is responsible for controlling harmful gases from being released in the air from the car’s exhaust system.


Added Expenditure

Replacing the standard exhaust system with a straight exhaust pipe system will lead to an increase in the cost of car maintenance. This can be avoided as all cars come with a pre-installed standard exhaust system which keeps them in good shape.


Turbo Back Exhaust Pipe

Turbo Back Exhaust systems include a part of the exhaust system that the turbocharger engine uses as the final outlet to the passage of open air. They are generally manufactured as part of the aftermarket systems for cars.


Pros of a turbo exhaust pipe

Extra Exhaust Flow

Cars that are turbocharged benefit from that additional flow of exhaust that is provided by a turbo-back system. These exhausts achieve an increased flow by broadening the pipe size and eliminating factory bends that were formerly confining the flow.


Higher Horse Power

Turbocharged cars also have an enhanced level of Horsepower. The improved flow with a larger diameter pipe will also help the turbo to reel much faster. You can complete this process with the addition of a custom tune and performance muffler. A striking difference can be observed after installing these components.


Cons of a turbo exhaust pipe

Expensive Installation Costs

The cost of setting up a turbo-back exhaust system is on the higher side. The average cost would range anywhere between $4500 and $5000. This value includes the turbo, the additional parts plus the labor costs. It’s definitely a costly affair.



Cat Back Exhaust Pipe

This exhaust pipe system runs from the rear end of the catalytic converters to the end of the exhaust system. The ‘cat’ actually refers to the catalytic converters. These pipes also have a sizeable difference from those that are pre-installed in the car.


Pros of a cat back exhaust pipe

Affordable Exhaust System

The Cat Back Exhaust system is certainly more affordable than the Turbo system or any other enhanced system other than the standard one with ideal sound levels. If you need an upgrade within a limited cost structure, the cat-back would be the best buy.



You can achieve a nicer sound from the exhaust if the cat back exhaust system has been installed in the car. The ideal muffler and piping structure enable the system to make a fascinating sound desired by many car enthusiasts.


Cons of a cat back exhaust pipe

Too Noisy

The noise caused by the exhaust may be ideal to the owners but over time, it may turn out to be excessive and unbearable. One way of evaluating the sound before buying is listening to them continuously on other vehicles.


Large Size

The size of these exhaust systems may not be ideal for all cars and may require additional adjustments incurring additional costs. Such products are marketed well but may not fit as represented in the marketing process.

Why do some cars have 2 exhaust pipes?

Some cars have two exhaust pipes because it helps in eliminating gases and combustion quickly thereby increasing the power of the car. The single exhaust system most commonly possesses ‘back force’ issues which can be combated with the use of a dual exhaust system.


What are the benefits of dual exhaust?

The main benefits of dual exhaust systems are gains in terms of performance, improved exhaust flow and reduced back coercion.


  • High Performance Gains

Robust exhaust systems will enhance the performance and offer a fascinating sound to go hand in hand with the built-up power


  • Improved Exhaust Flow

The overall exhaust gas flow is much higher than that of a single exhaust, even if the velocity may be slower. For huge, turbocharged engines, a dual exhaust system will support keeping everything cool thereby maintaining the best performance.


  • Lower Back Pressure

Dual exhaust gas systems help in reducing back pressure. This can save a lot of energy and also help in running the engine more efficiently for superior gas mileage.


  • Dynamic look

Dual exhaust systems provide the car a cool, aggressive and fun look, making it more appealing to the eyes.


Why do some cars have 4 exhaust pipes?

A few cars have 4 exhaust pipes only for aesthetic appeal. However, they use only 1 or 2 actual outlets for gas out of the four.

Some cars also have a 4-2-1 exhaust system. These numbers indicate the said arrangement.

Four pipes start from the head of the cylinder which further combines into 2 pipes with only one pipe steering to the catalytic converter and muffler. This process is termed ‘scavenging’ and the purpose of this system is to remove the maximum amount of exhaust gas from the cylinder as swiftly as possible.


Is single or dual exhaust better?

Most car owners accept that a dual exhaust will provide better performance in comparison with a single exhaust system. This is because two pipes are utilized by exhaust gases to exit from each manifold instead of only one. The gases can escape from the engine quicker and supply extra horsepower gains.

The counter pressure is also greatly reduced due to the utilization of dual exhaust systems, resulting in greater mileage and better engine competence.


Is dual exhaust louder than a single exhaust?

Dual exhausts have a characteristic to have a thundering, deep and husky sound as opposed to single exhausts. This kind of sound is desired by many muscle car fanatics.

Even if the sound that an exhaust generates does not correlate with performance, it still is a major deciding factor for many to choose between dual or single exhaust. Stock single exhausts don’t have that brawny sound directly. Multiple single exhausts produce a superior, intense sound note for a more dominating appearance on the road.

If you don’t need a loud exhaust, there are other exhausts available that will have a tolerable sound or contain an optional silencer that you can fix in your car to reduce the tone.


Does dual exhaust burn more gas?

No, dual exhaust systems do not burn more gas. It takes very little effort to run a dual exhaust engine proficiently.  The fuel burning rate is slower when the engine runs systematically. This means you don’t have to use a lot of fuel as required by a single exhaust system to travel the same distance.


How much horsepower does exhaust add?

An after-market exhaust can add 2HP to 50 HP. This wide range of power depends on the type of exhaust system selected.


How much does dual exhaust cost?

Dual exhaust systems cost anywhere between$300 and $5000. The cat back systems range between $300 and $1300 whereas Turbo back systems range between $500 and $5000.


Can you put dual exhaust on a 4 cylinder?

Dual exhaust can be added to a 4 cylinder but it will have to be custom designed from the header. This is because a 4-cylinder car will only possess a single manifold. If a dual exhaust system is added, it may result in slowing down the car.


Will dual exhaust void my warranty?

Adding a dual exhaust will not void the warranty of a car. Only when the car has an issue because of the installed dual exhaust system will the warranty will be voided.


Why do most cars have the exhaust pipe on the right side?

Most cars have exhaust pipes on the right side as they have a driver’s seat on the left side. The idea behind the placement is generally to balance the weight and also to help in keeping the heat and fumes away from the driver. These placements can also be changed as per the choice of the car owner with some additional spend.



It is now evident that a sound exhaust system is extremely important for the overall performance of a car regardless of the type of exhaust system installed in the car. It is also essential to select the ideal exhaust system that works best with your car engine. This will largely depend on the performance level anticipated to be achieved from the car.

The engineers of the automotive industry are endlessly experimenting and uncovering new ways to distribute power linearly, be it positioning of the engine or engaging specific electronic elements at one point  One day, there might not be a need for exhaust systems or it may solely be used to make the car look more appealing.

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