axle vs cat back

Axle Back vs Cat Back: How to Choose the Right One?

Owning an automobile grants us a sort of virtual, total freedom to choose where to wander. Each automobile exists to serve a function, fulfilling itself first as a tool to be used by the owner. As a secondary purpose, a car does indelibly serve to reflect a personality, and it carries with it a sense of design that is meant to evoke some pattern about the owner and deliver some image.

To those automotive aficionados, it is important to understand the emotional, personal, and sentimental aspects of modifying a car to properly debate one exhaust system over another.

Flowmaster 817511 Exhaust System | Amazon

Outlaw systems deliver an ultra aggressive interior and exterior tone and are suited to the enthusiast who wants the most aggressive components they can purchase.

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MagnaFlow 15155 Cat-Back Exhaust System | Amazon

MagnaFlow's dedication to engineering and manufacturing the finest exhaust systems makes for a superior sound and driving experience. Constructed of premium materials and carefully designed for the best fitment and performance, you can have confidence in making the right choice for your vehicle.

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02/19/2024 09:29 pm GMT

The secondary duality a car carries — the wholly personal — is where many of us enthusiasts can openly work and explore the easel that is a machine that is part art. Performance and technical capabilities are certainly one of the aspects of personality and uniqueness a car can have.

Having some modifications transforms a car in both a performance and artistic manner, generating one of the most satisfying moments: when a car is distinguished from the others both in performance and in its overall presence.

Enter exhaust modifications. There are several reasons to modify an exhaust. Being a rather pricey modification to delve into (and one you likely won’t be switching out as often as wheels, racks, or body fairings), it’s good to explore the options and determine which exhaust manifolds will work best for your needs and desires

At a glance, a quick comparison between axle-back vs cat-back exhaust systems makes for a good foundation in understanding how each exhaust system modification might be best for you. The following are the large highlights and takeaways from both companies.

The Main Differences Between Axle-Back vs Cat-Back Exhausts

The Main Differences Between Axle-Back vs Cat-Back Exhausts are:

  • Axle-back exhaust systems are purely artistic, in the sense that they modify a vehicle’s sound exclusively. The modification changes the sound of your car, but will highly likely not add any power to the car, whereas Cat-back exhaust systems can increase a car’s overall performance. So while cat-back exhausts can change the sound of a car, this is not the sole limit of functionality.
  • Axle-back systems are less expensive, whereas Cat-back exhaust systems are a lot pricier

Which Exhaust System is Right for You?

Provided the information highlighting the three largest differences between axle-back vs cat-back exhausts, it provides a context for further delving into why each major difference might or might not work for you. 

Following this more detailed insight into the specifics and nitty-gritty of the factor weighing process, the goal is that a decision will be much clearer, evident, and expedited with the right reasoning and assurance behind it. 

How Exhaust Systems Work

To best understand the reasonings for one exhaust system over another, it is readily imperative to understand how exhaust systems work and what they do for an automobile. 

For cars, exhausts serve to transfer exhaust gasses and byproducts produced during the combustion cycle within an engine. Exhaust systems filter exhaust fumes, control the noise made by an engine and improve an automobile’s performance. 

Axle Back vs Cat Back

Exhaust gasses are a part of the combustion cycle. The exhaust fumes have a slew of toxic outputs that are carried along a pipe into a catalytic converter, which filters out the toxic fumes, leaving carbon dioxide as a byproduct.

The carbon dioxide travels through the remainder of the exhaust through a muffler, which moderates the sound by channeling soundwaves into a quieter and unique pattern. Understanding these simple processes makes for an improved understanding of what to look for in an exhaust system.

Cat-Back Exhausts

Aftermarket cat-back exhausts are meant to replace and be an improvement from your previous exhaust. A cat-back exhaust is an exhaust system that runs from the catalytic converter itself all the way to the exhaust tip. Kits will include all necessary pipes, catalytic converters, and mufflers, and tips necessary. 

Some kits are even available with a muffler delete, which removes the presence of a muffler to allow for louder and more rugged sound from the vehicle. Deletes are only legal in some states, however, and are most often reserved for exclusive off-road use.

There are three central purposes a cat-back exhaust serves to fulfill: power, fuel economy, and sound. Power and fuel economy go hand-in-hand with the same concept originating around both. Given that an exhaust system is connected to the engine and is connected to the combustion cycle, think of the exhaust as a breathing tube. 

Cat Back System

Aftermarket cat-back exhausts improve how your engine breathes. With less work necessary to push out exhaust fumes, the improved airflow allows the engine to breathe easier, producing more power. Similarly, fuel economy is greatly enhanced by improved airflow, since the engine is not working as hard.

Because cat-back exhausts include mufflers and exhaust tips in their kits, the sound is modified along the way. Different tips and shapes of pipes, as well as the opening diameters of the pipes themselves, change the way sound travels, allowing one to customize that wonderful note an engine can produce.


  • Improved horsepower from improved airflow
  • Improved fuel economy from better airflow
  • Unique sound created by the exhaust


  • Improved horsepower resulting from reduced obstruction, and greater overall flow of exhaust gasses
  • Improved fuel economy also resulting from an engine’s reduced exhaust gas struggles
  • Different cores within catalytic converters are ideal for higher heat ranges generated by turbochargers or superchargers
  • Reduced weight of 20-30 pounds if replacing with lighter material pipes
  • A custom sound tuned to your liking
  • Highly customizable shapes and pipe sizes


  • They can range from as low as 300 dollars, to as high as well over a thousand dollars
  • The noise change can be disruptive on roads or to neighbors
  • Cheap jobs may use cheap materials that will corrode
  • Potential for warranty-voiding if the car is new

Customer Reviews of Cat-Back Exhausts

Axle Back vs Cat Back

Given the nature of cat-back exhausts, there is no one single provider, but there is a provided source to many of the experiences generally spanning the customers who have bought from multiple manufacturers.

  • When discussing a $1300 Borla-made cat-back exhaust system, many buyers stated that it was worth the performance upgrades, but that ultimately the sound achieved and quality of the product was over the top
  • Discussing a more affordable $325 exhaust made by MBRP, many customers expressed joy and content ownership due to the exhaust being a good fit, as well as having an improved custom sound without over-the-top loudness to it.
  • Regarding a 750 dollar MagnaFlow cat-back exhaust for a compact sport, the buyers tended to have a resounding appreciation and feeling of overall worth and money well spent due to fitment, sound, and performance for some.

Axle-Back Exhausts 

Axle Back Exhausts

Much like the cat-back exhausts, axle-back exhausts are meant to be an improvement from stock systems. Axle-back configurations differ from their catalytic converter-containing counterparts. 

Axle-back exhausts work by modifying the mufflers and exhaust tips present starting typically around the rear axle of the car. Provided that the muffler is in charge of bending and redirecting soundwaves to reduce and channel overall engine noise, modifying these specific components will certainly change the sound of the car, but its limit is customized sound.

This is perfect for those who are perfectly comfortable with the performance of their car and just want a customized exhaust note at an affordable price.

MagnaFlow 15160 Axle-Back Exhaust System Kit | Amazon

This is a Street Series performance exhausts are designed to enhance the power and exterior sound of your vehicle without sacrificing comfortable interior noise levels. 

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02/19/2024 05:35 am GMT


  • Exhaust system that is cheaper than its catalytic converter counterpart
  • Wide range of sounds to generate, truly being a highly customizable option
  • The parts are easy to install, and with minimal complex tools required


  • The overall affordability present in and due to less involved components. Anywhere from $200 to around $800, on average
  • Easier installation, given that many are bolt-on systems
  • A unique sound that gives a car a sound to match its look


  • No improved performance for those who might seek it
  • No weight reduction if weight reduction is incredibly important

Customer Reviews of Axle-Back Exhausts

Once again, several manufacturers offer axle-back exhausts, so the source provided allows for a view of many customers’ experiences

  • When reviewing a $423 Flowmaster exhaust, many customers left glowing reviews expressing their enjoyment of their easy to install and great sounding exhaust
  • A $250 SLP made exhaust received a general liking, while many also simultaneously gripped the notion that at high speed, the sounds droned or became raspy. One customer, unfortunately, had his Mustang’s bumper melted by the exhaust.
  • Reviewing a $750 Borla exhaust, many left stellar reviews with stellar experiences, agreeing that there was no drone or any noticeable flaw in the car’s sound. Overall the customers seemed to have had very positive experiences.
  • One $740 SLP exhaust garnered lots of flak for being droned, raspy, and overall poor quality despite the premium pricing
Flowmaster 817511 Exhaust System | Amazon

Outlaw systems deliver an ultra aggressive interior and exterior tone and are suited to the enthusiast who wants the most aggressive components they can purchase.

Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

Final Thoughts and Conclusions

Changing your car’s sound is at the front and center of the subject regarding exhausts. Both Axle-Back vs Cat-Back is going to improve your car’s sound and allow you different degrees of customization freedom — depending on what you choose to buy. The right choice will come down to needs or circumstances.

If you can afford to spend close to a thousand dollars or so for exhaust of extreme and outstanding quality, the best choice is definitely a cat-back exhaust. The reasoning goes as follows. Some premium axle-back exhausts can match the price of more affordable cat-back exhausts. 

With significant all-round performance upgrades provided by cat backs, it makes sense to steer in the direction of the sound, with added performance to enhance the ride, as well.

Axle-back exhausts are good for those who would prefer to save money and still achieve a sound that is beautiful and matching the art that is their automobile. Given their affordability and ease of installation, this is also handy for amateur mechanics and DIY-ers who would like to get more into working hands-on with their car.

Frequently Asked Questions (FAQs) About Axle-Back vs Cat-Back

Question: Are cat-back exhausts louder than axle-back exhausts?

Answer: In general, a cat-back exhaust will tend to be louder than an axle-back. What determines the overall sound will come down to individual center pipe sizing, as well as whether or not a resonator is present in the cat-back exhaust.

Question: Do cat-back exhausts add power?

Answer: Cat-back exhausts do add power, but not always to a grand degree. Paired together with a quality air intake, a performance chip, or a power programmer, it is very likely that you will notice significant power and performance improvements. Not only that, but the fuel economy is also likely to improve in the process.

Question: Does a straight pipe add horsepower? 

Answer: A straight pipe exhaust will greatly reduce the pressure of exhaust gasses the engine has to work against expelling. Given this cleared space and flow, both your torque and horsepower figures will increase significantly.

There are some caveats, though. The legality of straight pipes varies from state to state and even county to county. Given the noise, it may get you in trouble, and if muffler deletes are present, you may face further consequences.

Answer: Borla ATAK allows for much louder exhausts that also have better flow than even a straight pipe due to their multi-core technology implemented. Despite these louder modifications, the exhausts remain legal in all 50 states.

Borla 140591 ATAK Cat-Back Exhaust System | Amazon

Mount an offensive to regain optimum acoustics with Borla ATAK cat-back systems. Your modern muscle car will not only be performance-enhanced but also acoustically tuned to a loud, aggressive exhaust note.

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02/18/2024 05:20 am GMT

Wrapping It Up: Which is Best For You – Axle Back vs Cat Back

The exhaust note is a piece of machined music. It is the siren song of any automobile and vehicle, and as such, many enthusiasts modify it in different ways. There exist many ways to customize your sound, and some even boost a car’s performance, upping its vitality and creating a rejuvenation of sorts. 

Whichever route you choose to take, rest assured that the resources are available and that your unique choice is what makes the car as individual and independently voiced as the driver behind the wheel. We hope this guide has provided some clarity and allows you to venture into what you are looking to upgrade for that special ride.

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