How Does a Performance Exhaust Affect Gas Mileage?

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Normally, a car comes with all the necessary components it needs to function as supposed.

However, even though modern cars feature sophisticated technologies and accessories, for some people, there’s still a need for an aftermarket product.

Performance exhausts are poised to improve the “performance” of car engines. However, the major function of the exhaust system in every car is to control the noise from the engine when you start the car, or while driving.

So, how does a performance exhaust affect gas mileage? Well, aftermarket exhaust system manufacturers claim that their products can increase engine horsepower and improve gas mileage, but this is not entirely true.

This article explains – in detail – what to expect from aftermarket performance exhaust systems.

What Is Performance Exhaust?

Alright, so what exactly is a performance exhaust? Honestly, third-party auto parts manufacturers always find an “enticing” name to market their aftermarket products, while in the real sense, those products are practically as basic as you had thought.

A performance exhaust is almost the same as every other type of exhaust system you know.

The only difference between a performance exhaust and the standard (regular) exhaust system you know is a redesign of a “cat-back” (catalytic converter) section.

Yes, performance exhausts are typically bigger in size, but most other aftermarket exhausts systems are also bigger than stock exhausts.

Because of the redesigned “cat” section, most performance exhausts are also called “cat-back” exhausts.

Again, the basics of “performance” exhausts are to de-restrict airflow into the exhaust system and typically increase engine output. Well, this can also be achieved using cold-air intakes or headers.

But without saying much further about these typical exhausts systems, let’s talk about how they improve gas mileage.

How Does a Performance Exhaust Affect Gas Mileage?

How Does a Performance Exhaust Affect Gas Mileage

When you modify your car engine, it is important to also modify your exhaust system to allow easy airflow at high and low RPM.

While there’s nothing wrong with getting bigger exhausts for your engine, aftermarket exhaust systems can actually improve your engine’s performance and fuel consumption.

The key element that determines an exhaust’s performance is the velocity at which exhaust gasses from the engine exits the pipe.

Apparently, when the engine functions at low RPM, it releases low exhausts gas – the velocity is low, too – thus, using a smaller exhaust pipe on such an engine is all good.

However, if the engine’s RPM increases, it’d cause airflow restriction on smaller pipes.

What are we implying? Bigger exhausts pipes guarantee better “exhaust” performance and efficiency, as well as reduces noise.

Regarding gas mileage (and improving horsepower as some manufacturers claim), this is what you need to know.

Performance exhausts do not add anything more to your car; they only guarantee “Less restriction,” which means your engine can exhale a little easier.

It is this relief that makes your engine perform much better than it has been doing.

So, the performance exhaust added nothing, your engine had the capability all the while, the aftermarket exhaust only “unlocked” it, and not “adding to it.

Key Takeaway: Installing an aftermarket “performance” exhaust system can improve airflow to/from the engine, which in turn can improve your car’s engine performance, and possibly influence fuel economy.

What More?

It is important to note that the sound of exhaust does not have anything to do with fuel consumption.

In other words, louder exhausts do not mean more fuel consumption. If you noticed that your car’s fuel efficiency dropped, the engine is what needs to be checked.

Then again, exhausts scavenging can also help to improve the performance and efficiency of your car’s exhaust system; this could be cheaper than buying an aftermarket performance exhaust.

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