The Difference Between Axle-Back and Cat-Back Exhausts

One of the first modifications people make to their cars is an exhaust system. There are two different types of exhaust systems available, and each one has its benefits and drawbacks. In this blog post, we’ll take a look at the difference between axle-back and cat-back exhausts.

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Axle-back Vs. Cat-back

The easiest way to understand the difference between axle-back and cat-back systems is to think about where each part of the exhaust system starts.

The “axle” refers to the back, or rear, of the car (where you’ll find the wheels), and where it connects with the rest of your car; this connection point is called an “axle”. For example, on a 4-cylinder vehicle, there are four separate axes: one for each wheel.

On a V6 or V8 vehicle, there are two axles: one for even-numbered cylinders and one for odd-numbered cylinders. Finally, on a flat engine or motor that contains no distinct parts, such as a rotary engine or motorcycle engine, there is only one axle.

The “cat” refers to the catalytic converter, a device that uses catalysts and heat to break down harmful emissions before they can be released into the air as exhaust gases. In modern cars, this takes place not in the muffler but inside the exhaust itself.

Generally speaking, a cat-back system is simply an aftermarket exhaust with a visible component made from tubing connecting the axle to the muffler. As such, you’d use this term for any car that has a fully exposed section of tubing running from its rear end to where it connects with the actual muffler – anything apart from a true “axle-back”.

On an axle-back system, by contrast, the catalytic converter remains in place and there is no visible component extending from the axle to the muffler. These types of systems tend to be less expensive than cat-back systems and they produce a slightly louder sound than their counterparts.

It’s important to note that you can perform one modification without performing another: just because your car currently has an axle-back exhaust doesn’t mean you need to switch it out for a cat-back system; it simply means you’d enjoy some of the benefits of such a system (like improved fuel economy) by doing so.

Advantages and Disadvantages of the Axle-back Exhaust System

The major advantage of an axle-back system is its simplicity. Because it contains no components that extend from the axle to the muffler, it’s often less expensive and easier to install than a cat-back system. It also produces a louder exhaust note because you’re not replacing any pre-existing components that mute the sound.

However, this type of system does have a few disadvantages, particularly when it comes to performance. The primary drawback here is reduced fuel economy: while better than nothing, an axle-back system will cause your car to lose some of its peps compared to if you had kept things stock or added a cat-back system instead.

By installing only the very beginning portion of your aftermarket exhaust at first, you’ll be able to safely and effectively improve your vehicle’s overall performance while minimizing the impact on its fuel economy.

Advantages and Disadvantages of the Cat-back Exhaust System

The major advantage of a cat-back system is its improved fuel economy. Since it replaces the part of your exhaust system immediately behind the catalytic converter, you’ll be able to enjoy better power and better gas mileage than what you’d get with an axle-back system.

It’s also considerably more affordable than an axle-back system, particularly when compared with other aftermarket modifications such as cold air intakes and turbochargers.

However, because the catalytic converter remains in place and isn’t replaced, this type of exhaust doesn’t make nearly as much noise (or sound cool) as an axle-back system does; only by taking out the catalytic converter itself can you achieve a truly throaty tone.

This isn’t usually a concern with sedans or other types of cars, but if you drive a sport utility vehicle (SUV) or pick-up truck you might need to learn the specific procedures for removing your particular model’s catalytic converter.

Which Is Better? The Axle-back or the Cat-back?

When it comes down to choosing between an axle-back system and a cat-back system, there’s no right answer. Both types of systems offer their benefits and disadvantages; the choice is really up to you.

If your primary concern is performance, you’ll be better off with a cat-back system. If your primary concern is price, you’ll probably prefer an axle-back system (provided it doesn’t conflict with any noise ordinances in your area).

How To Choose Which Is Suited For You?

When deciding which type of exhaust system is right for you, it’s important to examine your priorities to decide which one will be more beneficial in the long run. Do you place a higher priority on performance or price? What about noise levels? These are just some of the questions that you’ll need to ask yourself when making this decision.

Performance vs. Price

If you’re looking for the absolute best performance possible, a cat-back system is your best option. If you’re on a tight budget, however, an axle-back exhaust might be more affordable in the short term but will ultimately cost you more money if it’s ever time to replace it with something better.

Noise Level

Similar to how performance is directly related to price when dealing with an axle-back system, the noise level is directly related to price when dealing with a cat-back system. The most expensive (and quietest) systems will also be the most restrictive; more affordable options are louder but still offer good noise suppression overall.

Type of Vehicle

The type of vehicle you drive can have a significant impact on what particular type of exhaust system is more beneficial. Sedans are generally better off with an axle-back system, while sport utility vehicles (SUVs) and pick-up trucks are almost always better off with a cat-back system.

Even then, however, your model may have special characteristics that alter the situation by requiring you to remove the catalytic converter for improved performance or include it in the exhaust system for noise level suppression.

Conclusion

In short, axle-back exhausts are designed to give a car a distinctive sound and performance boost. Cat-back exhausts provide more power but may not have the same unique “hum” as an axle-back does for those who want that particular noise quality.

If you’re ready to make your vehicle stand out from the pack or need help choosing between these two styles of exhaust system, feel free to contact us today! We can answer any questions you might have about your personal needs and preferences so we can recommend the perfect style of exhaust for you.