Cone Air Filter Vs Flat Air Filter

Same brand, same material – cone or flat?! That’s a question many people asked (including me). So in this article, we will compare both types of air filter in detail. You should be able to make a decision after this. Or at least gain new knowledge.

Quick answer – cone air filter is a better choice if you want a louder sound during acceleration. Cone air filters are not enclosed inside an airbox – allowing them to be louder and suck more air. However, they are harder to install compared to flat air filters.

Now that’s out of the way, let’s jump into the details. I will discuss what cone and flat air filters are, along with their pros and cons.

If you don’t already know, a car needs air to create combustion and deliver power to its wheels. To improve performance, you want to increase incoming air into the engine. 

A car engine sucks air from the surrounding – air which could be dirty – filled with dust, debris, sand and insects. You don’t want any of these to enter your car’s internal (otherwise, bad things happen). Which is why we use an air filter. Simple? 🙂 

Stock air filters that come with your car are usually made from paper. They work well in trapping air impurities but can be quite restrictive. They don’t allow as much air to flow through.

So to combat this, aftermarket manufacturers like K&N produce performance air filters. Ones which are made with oil-coated foam. They allow more air to pass through while also trapping impurities using oil. 

Now, this is what I don’t want you to confuse – a performance air filter can be flat or cone. It does not mean that every flat air filter is stock and every cone is performance. 

In this article, I will talk about the differences of cone and flat air filters. If you want to learn more about performance air filters in general, take a look at my other article. What Does A Performance Air Filter Do?

Flat air filters are the most common type of air filter. They are enclosed inside the car’s air box. Air is sucked from the car’s intake, flows to the airbox where it’s filtered and then enters the combustion chamber to generate power. 

Having an air box means that the noise of air flow will be muffled. Manufacturers purposefully design the airbox this way because the general population of drivers do not enjoy noisy cars. Only us car enthusiasts do.

Installing a flat air filter is easy – on most cars, you won’t even need any tools. Just pop open the clamp that holds the air box and then place your air filter inside (make sure you got the right air filter size too).

Here’s a flat air filter by K&N from Amazon, if you wanna check it out.

That’s literally all – it’s that easy. Here’s a YouTube video showing you how to replace a flat air filter.

Pros:

1. Easy to install. Flat air filter is super easy to install. You don’t need any screws or jacking up your car. Just unlock the air box clamp and place your air filter in. Did you watch the YouTube video I linked above? 
2. Keep hot air out. Installing a flat air filter means you still have an airbox in place. Which also means that only cooler air from the car’s intake can enter. Hot air from the engine bay doesn’t have an opening to enter the combustion chamber. 
3. No warranty impact. Replacing your air filter with another flat one won’t require you to modify anything. Which means all your car warranty is intact.
4. Lesser chance for wet filter. Being enclosed inside an airbox, your air filter will not get wet over rain or snow. Unless you just washed your performance air filter and immediately installed it on your car. Why would you?

Cons:

1. Muffled air flow sound. The airbox which encloses the air filter also acts as a silencer. You will not hear the unique sound of air rushing into your engine. You should check what the sound is like before making any decision. I will link it below.
2. Lesser air flow. Air can only enter from your car’s stock intake. This means you have potentially less amount of air flow into the system.

Cone air filter is larger than a flat air filter. They are shaped as a cone and replace your existing air filter and air box. This means a cone air filter is not enclosed inside an air box – allowing them to pull in more air.

When equipping  a cone air filter, you hear the sound of air rushing into your engine as you accelerate – a unique sound that makes cone air filters worth it (in my opinion). 

This happens because the airbox that was muffling the sound of airflow is removed. Listen to this YouTube video to know what sound I am talking about.

Installing cone air filters is more difficult than a flat air filter. This is because you need to remove the existing air box and replace the entire thing with a cone air filter.

You will also need to separate the Mass Air Flow (MAF) sensor from the air box and screw it onto the piping of your cone air filter. This is an important step because your car uses a MAF sensor to tell how much air is coming in, so it can inject the right amount of fuel.

Here are the steps of installing a cone air filter:

1. Unscrew your car air box
2. Unscrew the MAF sensor from air box
3. Attach MAF sensor to cone air filter (might need clamp)
4. Attach cone air filter directly to piping of throttle body 
5. Install heat shield (optional if you don’t want to suck in hot air)

Below are Amazon links to the cone air filters and heat shields that I personally have used.

• K&N Cone Air Filter
• Air Intake Heat Shield

If you are a visual person, here’s a great YouTube video showing you exactly how. It’s not that complicated – just more steps than the flat air filter.

Pros:

1. Looks great under the hood. Cone air filters can come in great colours – so when you pop open your hood, people can clearly see you have an aftermarket part installed. Aside from ego boost, it genuinely looks pretty cool too!
2. More air flow. Cone air filters have much wider surface area and they are completely exposed. This means more room for air in the surrounding to rush into the engine. Though, you will need a heat shield to prevent hot air from going in. I talk about this in cons.
3. Improved car sound. The sound of air rushing into the engine as you accelerate is just sweet. Did you listen to the YouTube video I linked above?

Cons:

1. Should use a heat shield. Being widely exposed, hot air from the engine bay is bound to enter the air filter. And if you don’t already know, hot air is less dense and has fewer oxygen particles. This means hot air can’t be used to generate big combustions – required for horsepower. You can overcome this by installing a heat shield around the cone air filter. 
2. Takes more time to install. To install a flat air filter, it’s just plug and play. To install a cone air filter, you need to remove the air box and make sure you still reuse the MAF sensor. Not that terrible but more steps. Refer to the installation video above.
3. More prone to water damage. Again, being widely exposed means that water from rain or snow could get your cone air filter wet. Although, I wouldn’t worry so much about this. Heat from the engine bay will get rid of the moisture real fast.

Most air filters (or performance air filters) are marketed to improve horsepower. Be it flat or cone, air filters will not give you much horsepower. Maybe 1-5 additional horsepower. You wouldn’t notice it though.

You install an aftermarket air filter because they are reusable. For significant horsepower you need to modify the entire car’s air flow system. This means the air intake (or filter), exhaust and downpipe, if you have turbo.

Most enthusiasts perform these modifications gradually. They start with air filters and move back into the exhaust. 

I just want to share this quick info, so you don’t get disappointed when your performance air filters don’t give you much performance.

So… did you catch all that info? Let’s summarize the difference between cone air filter and flat air filter in a table.

For sound and horsepower, I actually recommend you go for cold air intake instead. The sound improvement is much better and you are optimizing the whole intake system instead of just a part of it (just the air filter).

Similar to cone air filters, a cold air intake will not provide you with massive horsepower difference. However, the sound improvement is much more notable. Here’s an article about cold air intake and sound if you want to know more. Does Cold Air Intake Make Car Louder?  

A cold air intake can cost about $300. If you don’t have the budget, and still want the sound of air rushing into your engine, then you could look into drilling holes on your airbox instead. 

Correct holes on your airbox could reduce the muffling of the airbox. It could also allow more air to enter your engine. Just make sure you drill the holes on the side or bottom of the airbox. This way hot air from the engine bay won’t flow in.

Here’s a YouTube video showing you how to correctly drill holes on your airbox.