Single Exhaust Vs Dual Exhaust: Sound, Power, Weight & Dyno

Dual exhaust will sound louder than single exhaust and it will also improve your vehicle’s power. But, it will add extra weight to your car. Getting single or dual exhaust also depends on the type of engine your car is running.

I’m running a single exhaust with an aftermarket muffler on my old 90’s Civic, it sounded pretty awesome and I felt a lot more pulling power than before.

Whereas on my ‘86 Camaro, I’ve installed a big dual exhaust system to it, and I felt a bigger difference from this dual exhaust…

In this article, I will discuss about:-

  1. Whether you should get a single or dual exhaust and its benefits.
  2. The price and installation of these exhausts.
  3. Which is more suitable for a turbo installation.

Single Exhaust Vs Dual Exhaust

 

Single Exhaust Dual Exhaust
Horsepower Gain 15hp 30ph
Exhaust Backpressure higher lower
Exhaust Velocity lower higher
Weight low high
Sound Improvement Small improvement Big Improvement
Tune Required If aftermarket, yes If aftermarket, yes
Legal Yes Yes
Gas Mileage  Good Poor 
Cost Cheap to moderate High cost
Installation Easy More complex
Suitable For Turbo Yes Yes

Image of header back exhaust

Performance Improvement: Single Vs Dual Exhaust

Dual exhausts will improve your car’s performance better than single exhaust. This is why it is widely used in performance applications and is a very popular aftermarket choice.

Dual exhaust will also have lesser backpressure. This pressure is usually created by the engine to overcome the hydraulic resistance of the exhaust system to discharge the gas. 

If you want to maximize horsepower you have to minimize backpressure, so that the leftover air can get out of the cylinder faster for the next exchange.

A good dual exhaust may give you more than 30 horsepower, compared to the 15 of a single pipe exhaust system. 

Dual exhaust delivers gasses out of the engine faster, which will improve the overall combustion. I.e., getting more “used” air (exhaust) out at a time. The more air it can get out, the more the engine can suck in; thus, MORE POWER.

Sound Improvement: Single Vs Dual Exhaust

Dual exhaust will sound more characteristic and louder than single exhaust. It works better discharging gas from the engine with less backpressure, creating better rumbling sound in the process.

Engine configuration also plays a big role in producing sound. If you run a smaller displacement engine, the exhaust will not be as loud as a big displacement V8 Engine.

RELATED ARTICLE: Glasspack Mufflers 101: Sound, Power Gain & Are They Legal?

If sound improvement is your top priority, I recommend you checkout an aftermarket muffler instead – they are cheaper and provide equally good sound as aftermarket exhausts.

RELATED ARTICLE: Are Bigger Exhaust Louder?

Tune Required: Single Vs Dual Exhaust

A tune is required for installing single or dual exhaust in order to deliver the right performance. The ECU needs to be adjusted, as O2 sensors will have new readings of different backpressure rates.

Basic tuning cost at the shop will start from $200. But, many aftermarket exhaust sellers are offering tunes with their exhaust system. They are usually plug-and-play modules, you will need to plug it into your OBD port and it’s done.

Cars without proper tuning will have bad power delivery and fuel economy. You most probably will also get a check engine light on your dash. If you have aftermarket parts installed on your car, tune it if you want to avoid problems in the future.

RELATED ARTICLE: How Much HP Can You Gain From a Dyno Tune?

Legal: Single Vs Dual Exhaust

Single and dual exhaust are legal if they are properly made to accommodate all of the standards necessary to be road legal. You shouldn’t worry too much of their legality if your performance exhaust is made by a reputable brand. 

If your exhaust is fabricated by yourself at your house by using cheap tubing, without running any mufflers, you may get fined for not running factory equipment.

In the worst case scenario, authorities may ask for a car inspection, if the test fails, they might order you to put your vehicle to stock configuration and this process will usually take a long time.

You also need to ensure your exhaust meets the sound limit in your area to be legal. For example, California is notorious for having extremely strict laws on noise – anything above 95 dbA is illegal.

Here’s a link to the laws of different states in US regarding noise: https://www.semasan.com/resources/exhaust-noise-laws-state 

Gas Mileage: Single Vs Dual Exhaust

Single exhaust systems have better fuel efficiency compared to dual exhaust systems. They are usually installed on cars that consume less fuel and produce less power. Single exhaust system will make your car run more effectively and efficiently. 

Dual exhaust will give you a significant power increase because of the engine’s ability to breathe better. Thus, if you are trying to increase horsepower, dual exhaust may be worth the cost. 

Cost: Single Vs Dual Exhaust

Single exhaust systems are cheaper to fit in compared to dual exhaust systems, because they have lesser piping.

The dual exhaust may cost more than double the price compared to single exhaust. Dual exhaust is much more complex and has one more muffler at the back and this adds up to the price. 

There are also some solutions that implement a single muffler at the back for both exhausts, e.g., in the Audi R8 and the E46 M3.

After researching dozens of exhaust systems (both online and in person), I have got the Flowmaster Force II Exhaust on Amazon to be the best fit for my car.

Which muffler is your car right now?

Installation: Single vs Dual Exhaust

The installation for both exhaust systems is very easy to do with proper equipment. You’ll need to raise your car for better access underneath the car for fitting the exhaust system.

The most obvious difference with these exhausts is, with dual exhaust you get the exhaust gasses from two exhaust manifolds and with the single exhaust from only one.

Note: Get an exhaust system that is made compatible with your car, so you would not need extra fabrication and improvising. It is best to do some research before purchasing, it’ll definitely save you money and time.

Suitable for Turbo: Single Vs Dual Exhaust

Both exhaust systems are suitable for turbo application. On a turbo boosted engine, dual exhaust will make a significant difference because of the amount of air and fuel being pumped into the engine by the turbo. 

If you have a V6 or larger engine, you will definitely notice a lot of boost in horsepower.

Should You Install Single Or Dual Exhaust?

If you have a V8, go for a dual exhaust system. If your car is running on smaller engines, go for a single exhaust route.

It also depends on how you are driving your car. If it’s only for daily commuting, then fuel efficiency is what you’re looking for. I would say it is best to go for a single exhaust. If you’re planning to put your car on for a track run, and also want a cool sound. Dual exhaust is the right path for you. 

On my Camaro, I’ve had my dual exhaust system fitted in. I wouldn’t replace that V8 ruble for anything else, people just love it. The exhaust also improved the car’s performance as well.

RELATED ARTICLE: Best Aftermarket Exhaust

Final Thoughts

Always go for a reputable brand when it comes to aftermarket parts. They certainly do a better job than others, delivering a good quality exhaust system compared to the cheap alternatives.

We have a full article on this topic. If you are on the market for a new exhaust system, feel free to check it out and learn more about the options that you have.

RELATED ARTICLE: Best Aftermarket Exhaust

Chai WJ.

Chai WJ.

I am a car enthusiast and a passionate rider who loves to discover new places. Since the pandemic, I can't go to places and I started to blog and share information that I learned. I'm not easily distracted, I just... OMG, do I hear a Supra?

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