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What Does a Cold Air Intake Do [And How They Work!]

What Does a Cold Air Intake Do [And How They Work!]

Cars built after the 90s don’t have thermostatic intake systems. That’s why you’ve seen such a proliferation of cold air intakes since then. They decrease air’s temp as it enters the combustion chamber, delivering more oxygen.

Cold air has a higher density than warm air. So, it contains more oxygen per unit volume. Oxygen is a necessary component of combustion, and you need as much as possible.

Getting more oxygen in the combustion chamber ensures complete combustion once fuel enters!

How a Cold Air Intake Works

Cold air intakes decrease the air’s temperature by using specific design principles. Modern cars usually place their intakes in a high-pressure zone, somewhere in the engine bay.

The type of intake depends on whether your car has a forced induction system. If it’s naturally aspirated, its intake will utilize a different design.

They’ve designed them to enhance the flow of air while reducing its temperature. Only intakes that do both actually increase your vehicle’s power. If they’re restrictive, it would nullify any potential gains.

Most aftermarket intakes try to create laminar flow by forcing the air to flow in parallel. Making it enter like that decreases friction and resistance, so it’s more efficient.

We can only improve airflow so much before we’re limited by other parts of the engine. If we deliver too much oxygen, we may not have enough fuel in the chamber. You can augment your intake by tuning the car’s ECU, to increase fuel delivery.

Decreasing turbulence helps to reduce air resistance as it enters the intake system. Once it’s inside the intake, they’ve straightened the route to the chamber. Many intakes shorten the delivery path, to enhance efficiency, too.

Some utilize the ram-air principle to create positive pressure zones at high speeds. Once you’re driving fast, this pressure zone forces air into the car’s engine. That’s how it’s able to deliver a power boost and increase the engine’s horsepower.

Parts of a Cold Air Intake

Every car has a different design, so their intakes will vary. Most of them use the same basic parts, though. Learning how they work can help you identify quality parts if you’re shopping for them online.

The main component of any intake system is always the air filter. This is where enters the intake system before traveling through the assembly. Typically, you can find yours in a plastic box, somewhere in the engine bay. Sometimes, they’re metallic, so keep an eye out for them.

You can find yours by looking near the throttle valve assembly after you’ve popped the hood. If you’ve ever seen a vacuum filter, they look fairly similar. The filter prevents dirt and debris from getting into the engine.

A high-flow filter doesn’t resist the air as much when it’s entering the system. They’ll also remove all the dirt, so your engine receives pure oxygen.

The mass flow sensor is the next major component of a cold air intake. This monitors how much air actually gets into the engine whenever you’re driving.

You’ll usually find two types of mass flow sensors if you’re looking at modern cars. A vane meter looks like a flap, and it reacts to the air’s mass as it enters the engine. The more air entering, the further back the vane meter will go.

This movement is measured by it to change how much fuel the ECU injects into the engine.

The other type of mass flow sensor is a hot wire system. They work by monitoring the electrical resistance of a wire assembly. As the temperature increase, so does the wire’s resistance.

Throttle bodies are the final component of a cold air intake. You’ll find them behind the mass flow sensor, holding a throttle plate.

This is what you’re opening whenever you press down on the car’s accelerator. Every time you press down on it, it lifts the plate to let more air enter the engine.

Types of Cold Air Intakes

A basic assembly will only improve the engine’s performance a little bit. They’ll decrease air resistance by using a straight pipe.

They can even create intakes that use pressure zones, mixing the air’s temp. Many of them move the filter’s location so that it’s behind the bumper. Moving it away from the engine makes it easier to lower the air’s temperature.

Ram intakes utilize different principles to create positive pressure zones. That’s how they’re able to increase the flow that’s entering the engine.

Many of them increase their diameter to allow higher rates of flow without resisting them as much.

Is a Cold Air Intake Bad for Engine?

Cold air intakes don’t harm your engine as long as you’ve installed them properly. They can actually decrease the wear on your engine.

A regular intake doesn’t let enough air enter to combust all the fuel. So, gunk gets left behind because there isn’t sufficient oxygen. Over time, this gunk can wear out your engine’s components by increasing friction.

Installing a cold air intake can improve the engine’s performance. Stock intakes restrict airflow, inhibiting horsepower in the process. That’s why your engine doesn’t accumulate as much gunk if you’ve installed one of them on your car.

You upgraded the car’s intake and increased its efficiency. So, more of its fuel combusts whenever it’s in the chamber, minimizing gunk.

Do Cold Air Intakes Increase Horsepower?

You can see a reliable increase in an engine’s horsepower after you’ve installed a cold air intake. You’ll get a chance to see how it works if you hook the car up to a dyno. They’ll measure a car’s horsepower, precisely.

If you measure a car’s power before replacing its intake, you’ll have a good baseline. Compare that to its power after replacing its intake to see how much it increased.

Most of the time, you’ll see a 10 HP boost if you’ve upgraded to a cold air intake. Some cars can see boosts of up to 30 HP if they had restrictive intakes before the replacement.

At a minimum, you’ll get a 5 HP bump by upgrading its intake.

Do Cold Air Intakes Really Make a Difference?

Cold air intakes actually increase the power of your engine, using sound engineering. They’ve designed them to deliver more oxygen, so your fuel fully combusts. That’s why they’re able to increase your car’s power if you install one of them.

They’re able to enhance the amount of oxygen entering the combustion chamber in a few ways. Most of them decrease the resistance by reducing the distance from the filter to the chamber.

They also move the engine’s filter away from its location, so it’s somewhere cooler.

Lowering the air’s temperature causes it to become denser. Dense air contains more oxygen molecules in a given volume than warm air.

Engineers may design them so that they use laminar flow to decrease air resistance, too. That’s when they’ve made the airflow, mostly, in parallel. Getting the air to flow like that makes it flow much more smoothly.

Are Cold Air Intakes Worth It? (Cover Pros and Cons)

Installing a cold air intake may be worthwhile, depending on your engine. They’ve got a ton of benefits if your car has a restrictive intake.

Replacing it would open up things up to let more air enter the system. Plus, it would contain more oxygen once it arrived in the combustion chamber.

You would also notice a boost to your vehicle’s horsepower if the intake increased its flow rate. Lowering the air’s temperature can boost your horsepower by up to 5% if you increase the flow enough.

There are only a few downsides when you’re considering a cold air intake. You’ll need to have enough room to install one of them in your car. Otherwise, replacing the stock intake may not be possible.

Another downside would be how much they’ll boost your engine’s performance. Most of the time, you’ll only see a slight increase in your car’s power after replacing its intake.

Other parts limit the boost in a lot of instances. Replacing the intake could deliver too much oxygen. So, you’d need to upgrade the car’s injectors to make sure there’s enough fuel to compensate for it.

How to Choose a Cold Air Intake

Choosing the right intake for your car isn’t too difficult. The first thing you’ll have to do is take a look at your owner’s manual. If you look in the back, you’ll find what type of intake the car needs.

Then, you can compare options by searching for them online. Most of the time, you’ll only have a few options for a given make and model.

Look for one that’s able to use ram-air principles. These increase oxygen delivery by creating a positive pressure zone at high speeds. They can boost your car’s power more than a regular cold air intake.

K&N designs many cold air intakes, so they’re a great place to look. Many of them use their innovative high-flow filters. Getting one of them means you’ll also get to use one of their filters, too.

If you’re not able to find one that uses ram air principles, don’t worry. You can still use one that’s able to decrease the air’s temperature as it enters your engine.

As long as it’s able to do that, you’ll notice a power boost once you’re on the road!

Do Cold Air Intakes Work for a Diesel?

You can use a cold air intake on a diesel engine if you’d like to modify one of them. Many diesel engines benefit from a cold air intake, even more than conventional engines.

Installing one of them on a diesel engine can even improve your fuel economy while you’re driving. That means you’ll spend less at the pump if you replace the engine’s intake.

Another way replacing it can benefit you is by improving the engine’s acceleration. You’re able to get more oxygen into the chamber whenever you press down on the accelerator. So, the engine will feel like it’s more responsive after upgrading its intake.

You will also notice a boost to the engine’s horsepower after getting a new intake. They’ll increase the horsepower by up to 12 HP in certain circumstances.

Why You Should Consider a Cold Air Intake

Replacing the intake on your car can improve its performance and efficiency. They’re able to get more oxygen into the combustion chamber, enhancing combustion.

Fully combusting fuels generate more power than leaving some behind. So, they can boost your performance!

Plus, you won’t have as much gunk in the engine, either. That’s because most of the fuel combusts when you’ve got a cold air intake. This can also boost your fuel economy since none of the fuel goes to waste.

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Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!