Car air filter - why is it needed and when to change?
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Car air filter - why is it needed and when to change?

Everyone knows that the combustion process requires the presence of three factors: a fire source, a combustible substance and air. When it comes to cars, the engine needs clean air. The presence of foreign particles in the cylinders is fraught with a rapid failure of the entire unit or its parts.

An air filter is used to purify the air entering the aspirated carburetor or intake manifold of an injection engine. Some motorists believe that there is no need to change this consumable often. Consider what function the part performs, as well as some recommendations for replacing it.

Why do I need an air filter?

For the engine to work efficiently, fuel must not just burn. This process must be accompanied by maximum energy release. For this, the mixture of air and gasoline must be in a certain proportion.

Car air filter - why is it needed and when to change?

So that the fuel is completely burnt, the air volume must be approximately twenty times greater. An ordinary car on a segment of 100 km. consumes about two hundred cubic meters of clean air. While the transport is moving, a huge amount of solid particles gets into the air intake - dust, sand from the oncoming or next car in front.

If it were not for the air filter, any motor would be out of order very quickly. And the overhaul of the power unit is the most expensive procedure, which in the case of some cars is identical in cost to buying another car. To avoid such a huge expense item, the motorist must install a filter element in the appropriate place.

In addition, the air filter prevents the noise from the intake manifold from spreading. If the element becomes heavily clogged, it will allow less air to pass through. This, in turn, will lead to the fact that gasoline or diesel fuel does not completely burn out.

Car air filter - why is it needed and when to change?

This disadvantage affects the cleanliness of the exhaust - more poisonous gases and pollutants will enter the atmosphere. If the car is equipped with a catalyst (for the importance of this detail, read here), then its resource due to this problem will be significantly reduced, since soot will accumulate too quickly in its cells.

As you can see, even such an insignificant element as an air filter can help keep the car engine in decent condition. For this reason, it is important to pay sufficient attention to replacing this part.

Types of air filters

There are two main types of filters. They are classified according to the material from which the filter elements are made.

The first category includes cardboard modifications. These elements do a good job of retaining small particles, but they do not do well with microscopic ones. The fact is that many modern filter elements have a partially fluffy surface. This effect is difficult to achieve with paper filters. Another disadvantage of such modifications is that in a humid environment (for example, heavy fog or rain), small drops of moisture are retained in the filter cells.

Car air filter - why is it needed and when to change?

The paper will swell when it comes into contact with water. If this happens to the filter, then very little air will enter the engine, and the unit will significantly lose power. To eliminate this effect, auto parts manufacturers use special water-repellent impregnations to retain moisture on the surface of the corrugation, but without deforming the element.

The second category of filters is synthetic. Their advantage over the paper counterpart is that they better retain microscopic particles due to the presence of microfibers. Also, upon contact with moisture, the material does not swell, which allows the element to be used in any climatic zone. But one of the shortcomings is more frequent replacement, since such an element clogs faster.

There is another type of filter, but it is most often used in sports cars. It is also a synthetic modification, only its material is impregnated with a special oil that improves adsorption. Despite its high cost, the part can be used a second time after replacement. But before installing it, the surface must undergo a special treatment.

What are the types of air filters?

In addition to classification by material of manufacture, air filters are divided into the following types:

  1. The body is made in the form of a cylinder. This design depends on the type of air intake. Most often, such parts are installed in diesel vehicles (sometimes they are found in passenger cars with a diesel internal combustion engine, but mainly on trucks). Filters of zero resistance can have a similar design.Car air filter - why is it needed and when to change?
  2. The body is made in the form of a panel in which the filter element is fixed. Most often, these modifications are cheap and used by default. The filter element in it is paper with a special impregnation, which prevents deformation of the contact surface in contact with moisture.Car air filter - why is it needed and when to change?
  3. The filter element has no frame. A similar type is installed in most modern cars, like the previous analogue. The only difference is the design of the module where such a filter is installed. These two modifications have a large filtration contact area. They can use reinforcing wire (or plastic mesh) to prevent deformation.Car air filter - why is it needed and when to change?
  4. Ring-shaped filter. Such elements are used in engines with a carburetor. The main disadvantage of such filters is that they occupy a large area, although air purification in them is carried out mostly in one part. Since when air is sucked into the material, there is sufficient pressure to deform it, a metal mesh is used in the construction of this type of parts. It increases the strength of the material.Car air filter - why is it needed and when to change?

Also filters differ from each other in the degree of purification:

  1. One level - paper, impregnated with special water-repellent substances, folds like an accordion. This is the simplest type and is used in most budget cars. A more expensive analogue is made from synthetic fibers.
  2. Two levels of cleaning - the filter material is identical to the previous analogue, only on the side of the air intake, a coarse cleaning element is installed in its structure. Usually, this modification is preferred by lovers of frequent off-road driving.
  3. Three levels - standard material with a pre-cleaner, only static blades are installed in the filter structure on the side of the air flow inlet. This element ensures the formation of a vortex inside the structure. This allows large particles to accumulate not on the surface of the material, but in the filter housing, at the bottom.

When is it time to change the air filter?

Most often, the need to change the filter is indicated by its external state. Any motorist can distinguish a dirty filter from a clean one. For example, if oil has appeared on the surface of the filter material or a lot of dirt has accumulated (usually air is sucked in one part of the part, so the periphery often remains cleaner), then it needs to be replaced.

How often to change the air filter in the car

As for the frequency of replacement, there are no hard and fast rules. The best option is to look in the service book and see what the manufacturer of a particular car recommends. If the vehicle is operated in slightly polluted conditions (the car rarely drives on dusty roads), then the replacement period will be long.

Car air filter - why is it needed and when to change?

The standard service maintenance tables usually indicate a period from 15 to 30 thousand kilometers, but this is all individual. However, if the machine is under warranty, then it is necessary to adhere to this regulation, or even replace it more often.

Many motorists change the air filter when they drain the engine oil and fill in a new one (regarding the oil change interval there is separate recommendations). There is another strict recommendation that applies to diesel units equipped with a turbocharger. In such motors, a larger volume of air passes through the filter. For this reason, the life of the element is significantly reduced.

Car air filter - why is it needed and when to change?

Previously, experienced motorists would manually clean the filter by flushing it with water. This procedure makes the surface of the part cleaner, but does not clean the pores of the material. For this reason, even a "refurbished" filter will not provide the required volume of fresh air. A new filter is not so expensive that a motorist cannot afford to purchase such a "luxury".

How to replace the air filter?

The replacement procedure itself is very simple, so even an inexperienced motorist can handle it. If the car has a carburetor type motor, then the element is replaced in the following sequence:

  • Above the motor is the so-called "pan" - a disk-shaped hollow part with an air intake. There are mounting bolts on the module cover. Depending on the brand of the machine, these can be nuts, or “lambs”.
  • The cover fastening is unscrewed.
  • A ring filter is located under the cover. It is necessary to carefully remove it so that particles from its surface do not get into the carburetor. This will clog the small channels, which will require additional waste on cleaning the part.
  • To prevent dirt from entering the carburetor during the following procedure, cover the inlet with a clean rag. Another rag removes all debris from the bottom of the "pan".
  • A new filter is installed and the cover is closed. It is worth paying attention to the marks that can be applied to the air intake housing.
Car air filter - why is it needed and when to change?

A similar procedure is carried out for injection engines. Only the design features of the module in which the replaceable element is installed differ. Before placing a new filter, you must clean the inside of the case from debris.

Next, you need to pay attention to how to place the filter itself. If the part is rectangular, then it cannot be installed otherwise. In the case of a square design, pay attention to the arrow located on the air intake. It indicates the direction of the flow. The ribs of the filter material should be along this arrow, not across.

Best air filters for a car

Introducing the latest rating of air filters for cars:

Company:Brand rating,%:Reviews (+/-)
Man9238/2
VIC9229/1
Bosch9018/2
filters8430/4
Mahle8420/3
MASUMA8318/3
SCT7924/5
J.S. ASAKASHI7211/4
SAKURA7022/7
Goodwill6021/13
TSN5413/10

The rating data is based on customer reviews who have used the products throughout 2020.

Here is a small video comparison of several seemingly similar filter modifications:

Which filters are better? Comparison of air filters. Air filter quality

Questions and answers:

What are the filters for cars? In all systems that require a clean working environment. This is a filter for fuel, air into the engine, oil for internal combustion engines, oil for the box, for cleaning the air entering the car interior.

What filters need to be changed in the car when changing the oil? The oil filter must be changed. In some cars, the fuel filter is also changed. It is recommended to change the air filter as well.

One comment

  • anonym

    Innovation or innovation in filters The goal is to create custom and reusable filters and save money on filters

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