Air filters, when and how to change them? The complete guide!

The air filter is an essential component (usually made of paper in the case of original air filters) for keeping your engine running smoothly. It prevents unwanted particles such as dust, pollen and debris from entering theair intake system, where they could damage the engine. By protecting the engine from these contaminants, it helps to ensure more efficient combustion and contributes to good engine performance.

BMC air filters (known as sport air filters) in particular, are designed to offer improved airflow over 'stock' filters thanks to their oiled multi-layer cotton construction, a material that performs better than traditional paper filters. It's very important to bear in mind that a clogged filter can lead to a drop in power and increased fuel consumption, or even engine problems.

The different types of air filter

There are three main types of air filter, each offering specific advantages in terms of performance, durability and maintenance:

• Paper air filters: This type of filter is the most common and is often fitted as standard in production vehicles. It is a single-use filter and must be replaced regularly. Its low reusability makes it less economical in the long term and more polluting.
• Foam air filters: Used mainly in off-road applications, foam filters are washable, but are often less effective at retaining fine particles.
• Oiled cotton air filters: This type of filter, like BMC air filters, offers a durable, high-performance solution. Made from several layers of oiled cotton, these filters optimize airflow while filtering out impurities. Unlike paper filters, they are washable and reusable, making them an economical and ecological choice in the long term.

 

What's more, the ability to maintain superior airflow helps to improve performance, particularly in high-performance vehicles or after engine reprogramming, such as that offered by Shiftech.

BMC air filters are designed for motorbike and automotive performance enthusiasts. Unlike traditional paper air filters, they allow increased airflow, improving combustion and engine performance while being washable and infinitely reusable. These filters offer both longevity and long-term economic benefits.

Unique design for optimum performance

BMC air filters use oiled multi-layer cotton to effectively filter particles from the air while allowing maximum airflow to the engine. This design is enhanced by an epoxy coating, which protects the filter from moisture and corrosion, extending its life. Unlike paper filters, which restrict the passage of air when clogged, multi-layer cotton offers high dust permeability, allowing optimum combustion and therefore better engine performance. This is particularly beneficial for sports or reprogrammed vehicles, where air intake is vital to maximize power.

Air filters and engine power

You'd think that a sports air filter would make your engine more powerful, and it's true. Yes, an air filter will improve your vehicle's performance. You shouldn't expect to gain as much horsepower as a stage 1 engine reprogramming, but it's in the detail that you get a perfectly optimized machine.

Sport air filter for Golf 7 2.0 L TSI

To illustrate our point, let's take the case of a 2017 Volkswagen Golf VII 2.0 L TSI.

As you can see, simply fitting a sports air filter slightly increases the power of your vehicle. This 5bhp increase was generally observed in all the tests we were able to carry out on a full range of petrol and diesel vehicles.

There is also a slight improvement in sound. In fact, you can hear the intake slightly more, which gives the vehicle a slightly sportier sound, which is all to the good!

Proper maintenance of an air filter is crucial to ensuring optimum engine performance and longevity. However, it's important to know when to replace or clean it to avoid any drop in performance.

Signs that your filter is clogged

There are several indicators that your air filter is clogged and needs servicing:

• Reduced performance: You'll notice a drop in engine power, especially during acceleration.
• Increased fuel consumption: A clogged filter can hinder the engine's efficient combustion, resulting in higher fuel consumption.
• Abnormal engine noises: The engine may make unusual noises, such as a whistling sound or sounds coming from the air intake, indicating a blocked filter.

In dusty environments or when driving in difficult conditions, the filter may become clogged more quickly, requiring more regular maintenance.

Frequency of air filter replacement or cleaning

Air filter cleaning or replacement varies according to the manufacturer's recommendations and the vehicle's operating conditions. In general, it is recommended that they be replaced every 20,000 to 30,000 kilometers. However, if you drive in dusty environments or with a lot of traffic, it may be necessary to check and clean it more frequently.

Keeping a filter clean ensures adequate air flow to the engine, optimizes combustion and helps to preserve engine life while reducing fuel consumption.

 

Regular maintenance of an air filter is essential to maintain good engine performance and ensure a long filter life. A clogged filter leads to reduced efficiency and can even cause long-term engine damage.

5 Steps to replacing an air filter

Changing or cleaning an air filter is a relatively simple operation that you can carry out yourself by following these steps:

1. Locate the filter : The air filter is usually located in a plastic housing, often near the engine. Consult your owner's manual for instructions specific to your vehicle.
2. Open the filter housing: Unscrew or remove the clips that hold the housing in place.
3. Remove the old filter: Remove the old filter, noting its position. Inspect it for dirt or damage.
4. Cleaning or replacement: If your filter is made of foam or washable cotton, you can clean it with a specific product. If it is a disposable paper filter, replace it with a new one.
5. Re-installation: Replace the filter in the housing and make sure it is correctly positioned. Close the housing and secure it.

 

Products and tools required for cleaning

If you are using a washable air filter, it is important to follow specific instructions to prolong its life. Here are the key steps for maintenance:

• Cleaning: Use a suitable cleaning kit, such as those available for cotton air filters. Gently rinse the filter in cold water, then apply a special cleaner designed to dissolve dust and oil residues.
• Drying: Allow the filter to air dry completely before using it again. Do not replace it until it is completely dry, as moisture could damage the engine.
• Oiling: If you are using a cotton filter, apply a light coat of filter oil to maximize its ability to trap impurities.

 

Regular maintenance ensures that the air filter retains its efficiency over the long term, optimizing performance and reducing the cost of buying new filters.