Key Difference: Axle-back and cat-back are systems that refer to the portion of the exhaust system. Axle-back system just refers to the muffler and the tips, while cat-back system includes the entire piping including the mufflers, tips, resonators, and exhaust pipes.

Car aficionados are always looking to upgrade their cars and add a little extra, either to give it a more aesthetic appeal or to give it a powerful performance and extra speed. DIY helps these people safe a whole lot of money and let’s them mix match the parts depending on what they want on the car. However, for people who are just looking to get started in this field there are a few words that are confusion. One such confusion arises when deciding to change the exhaust system: Should they go with axle back or cat back? Well, these two systems are different from each other in terms of from where should the replacements start. Let’s look at it in a little more detail.

The car exhaust system is usually just a piping that guides the exhaust gases away from the combustion to the outside of the car through the tail pipe. When the engine burns it releases exhaust fumes such as carbon dioxide and other gases as a result, these gases cannot be left inside the engine and are required to be led away from the engine to the back of the car, where it is released in the air. This is the job of an exhaust system. Depending on the type of engine, the exhaust pipe may flow through any of these locations: Cylinder head and exhaust manifold; a turbocharger to increase engine power; a catalytic converter to reduce air pollution; a muffler (North America) / silencer (Europe), to reduce noise.

Axle-back and cat-back are systems that refer to the portion of the exhaust system. Axle-back system just refers to the muffler and the tips, while cat-back system includes the entire piping including the mufflers, tips, resonators, and exhaust pipes. Now, if a person went to purchase an axle-back system, he would only be purchasing the mufflers and the tips, while when purchasing a cat-back system, he would purchase a whole exhaust system.

Obviously cat-backs are expensive to purchase and are trickier to replace as it would require taking apart the whole set just before or just after (depending on how the person looks at it) the catalytic converter. The axle backs are simpler as it would only taking apart and replacing the muffler and the tips. Axle backs are commonly replaced when the muffler/silencer stops working and the car starts to produce loud noises.

Many enthusiasts claim that replacing the cat-back system gives the car a gain in horsepower by either 5 or 10hp, while others claim that it does not give any hp gain but does improve the sound of the car. Depending on what the person desires when making alterations to their ‘ride’, they can either go for the cat-back or the axle-back.

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