What you need to know about the car air filter

How To

Each car owner has his own views on the proper maintenance of his own vehicle.

After all, on the one hand, there is the automaker’s regulations, which specify clear mileage and intervals for the replacement of those or other consumables.

But on the other hand, there are real operating conditions, which often do not coincide with the regulations, due to which the parts wear out before the term stipulated by the manufacturer of the car.

And in such a situation, it is correct to perform unscheduled work, instead of waiting for the specified mileage or time. It is important to know your car, to feel it, and sometimes even by circumstantial signs to understand that it is time to change certain components, to take off worn-out consumables and buy new ones in their place.

One of the most important consumables necessary to ensure the correct and efficient operation of the engine is the air filter. Do not underestimate the importance of this component. And it is extremely important to know how to correctly choose such an element that corresponds specifically to your vehicle. Read more: How do I choose an air filter for my car?

Air filters for the car, why are they needed?

The power unit installed under the hood of the car needs quite a lot of air. And it must be pre-cleaned in order to do its job properly. Air, and more precisely oxygen, plays a key component in the process of formation of the air-fuel mixture and its subsequent combustion.

On average, an engine consumes at least 15 liters of air per liter of fuel. And it must be of high quality. The air filter performs the task of providing the quality of the air flowing into the engine. It shouldn’t be confused with the cabin air cleaner, as the latter is aimed only at filtration of the air coming into the cabin. The direct connection to the power unit makes it clear what exactly the air filter in cars affects. It is aimed at providing the engine with the clean air it needs to burn fuel and power the cylinders.

Such elements are made from a variety of materials. But they all serve to filter the outside air. The filter traps dust, dirt, and other types of contaminants. The device goes into action as soon as the driver starts the engine. And it only stops functioning when the engine is turned off. Even if you don’t wash the car for a few days, and especially drive on a dusty road, you will see how much dust settles on the body. And some of that debris makes its way into the underhood space.

Without a filter, the dirt would enter the engine, get into the oil, and cause activewear on pistons, bearings, crankshaft, and other rubbing components. It would thereby reduce the life of the engine.

In fact, the air filter is a barrier or deterrent between the engine’s interior and the outside environment. Despite the status and cost of the car, none of them can be fitted with a perpetual cleaner. The consumable is so called because it is capable of serving a limited period.

Gradually, the filter gets dirty and clogged, not allowing the required volume of air to pass. And if the engine starts to lack oxygen, it will immediately have a negative effect on its performance. It’s not enough just to put a quality cleaner. You also need to keep a close eye on its condition, and if it shows signs of wear, replace it.

Features of the air filter device

Every motorist is required to understand the structure of the air filter used, which works for the benefit of the entire car and its engine, in particular. The standard air filter is presented in the form of a square, rim or rectangle, and on the perimeter of the structure there are special honeycombs, designed to filter the air flowing into the engine.

The filters are provided with 2 seals, and in the middle, there is a special material with filtering properties. Most of the consumables sold use cellulose fiber supplemented with a special impregnation in the role of filtering material.

This impregnation protects against moisture, fuel, and oil fumes. If the filters are of a more expensive category, characterized by better characteristics and quality, the paper is replaced by synthetic materials. Thanks to synthetics, even more contaminants from the external environment can be contained.

Also, synthetic has less resistance than cellulose. It also has its advantages, because the filter allows more air to pass through while maintaining high air purification efficiency. Understanding the working principle of this element is quite simple. Outside air in the environment enters through a special spigot designed specifically for air intake for the purpose of its further entry into the engine. All this volume of air intake first undergoes a purification process.

The filter is installed in such a way that the untreated air cannot bypass the filtering stage. The filter itself accumulates on itself the particles of impurities which got into the air intake together with the taken air, and already in the cleaned form, the air masses appear in the intake manifold of the power unit.

Then pure oxygen is mixed with fuel, the fuel-air mixture is formed, etc. Without the filter, dirty outside air would end up in the engine, which would lead to very quick contamination, wear and subsequent failure. For this reason, the filter is rightly considered an important and necessary component that is directly involved in the engine’s operation. Varieties When choosing air filters for cars, it is important to consider in advance what type is suitable for your particular vehicle. Externally, many filters look the same. But in practice, there can be a huge difference between them.

Manufacturers continue to work actively to improve the design and structure of the air filter, applying new materials, using innovative developments. Synthetic microporous material characterized by increased strength and durability is now actively used.

Synthetics is noticeably superior to conventional paper, although it costs a bit more. In order to retain water, fuel vapors, and oils, for the cleaner not to lose its effectiveness and not to wear out quickly, manufacturers use special impregnations.

It is impossible not to mention the technology of depth filtration. It implies the use of three-layered synthetic paper, which has a gradual reduction in pore size from the surface layer to the middle of the consumable.

The large pores first retain the larger particles, and then the fine contaminants are stopped. Thus, at the inlet to the collector, almost perfectly clean air with an optimal temperature is obtained. Filters are classified according to several criteria. One of them is the shape of the product.

Here you can select the following categories:

  1. Circular. They are also circular. This is an old type of air filter, which can now be found almost only on carbureted power units. When air enters the filter, there is quite a high pressure, which is why many consumables are supplemented with aluminum frames to increase the strength of the construction. But such cleaners are characterized by a small filtration area, and the design itself requires a lot of space for placement.
  2. Panel cleaners. They are divided into frameless and frame products. Currently the most common, are actively used as part of diesel and injector power plants. Some models, in order to increase strength, are reinforced with a frame of plastic or metal mesh. This further reduces vibrations and prevents deformation of the cleaning layer itself. They are compact, durable, take up minimal space, very easy to use and easy to change.
  3. Cylindrical. They require less space than their ring counterparts. But the surface area of cylindrical products is quite impressive. Such filters are mainly used for installation on commercial vehicles equipped with diesel engines. But they can also be found on some diesel passenger cars.

Another classification principle divides air filters according to the number of degrees of purification.

Here we can safely say that the more degrees, the more effective the element is. But it’s not always the case that the machine needs the most multi-stage cleaning.

  1. One degree. The simplest version of the air filter, consisting only of special paper. It is laid in the form of an accordion. In this case, the filter element is affected by all the available load.
  2. Two degrees. Directly before the cellulose or synthetic paper, a pre-cleaner is provided. This is a synthetic-based material that serves to trap the largest particles. Such filters are suitable for heavy-duty machines. Therefore, it is recommended to install them on off-road vehicles, crossovers and other cars that regularly find themselves in off-road, unpaved and sandy roads.
  3. Three Degrees. Before passing through the filter, the intake air goes through a pre-cleaning stage due to the cyclone principle of rotation. The incoming trash particles, like the air flow itself, gradually lose their energy, and begin to settle inside a special container. The swirling is created by a special design of the consumable, or by the impeller on the filter. It sets the desired direction of air flow.

Separately from the others, zero-resistance filters, or simply zero-zero-vortex filters are considered. The zero-impedance filter differs in that it has multiple impregnations of its filtering material, which is placed between two aluminum grids. The name is due to the property of letting a lot of air through with minimal resistance and without deteriorating filtering properties.

Such elements are usually installed on sports cars and cars with forced engines. In everyday life, for a measured and unpretentious drive, there is absolutely no need for a zero-levick filter. They are very expensive and justify themselves only if you use all the potential of a really powerful motor. The plus side of the consumable is that with it, the engine will definitely not encounter the effect of oxygen starvation.

Why is there a regular replacement?

You can often observe situations when the motorist periodically changes the oil, installs a new cabin filter. But the air cleaner is completely ignored, considering that it was there and will be there during the whole service life of the car. In practice, it is a consumable, which has a limited resource in many respects. During the operation of the engine, there are processes of fuel combustion. To be more precise, a mixture of air and fuel burns. The amount of air which enters the combustion chamber has a direct impact on this phenomenon. All engines installed on cars are divided into atmospheric, compressor or turbocharged.

The operation of atmospheric engines somewhat resembles a vacuum cleaner, as it draws air inside the cylinders. The movement of the cylinders themselves provokes rarefaction, which ensures the penetration of air masses inside the internal combustion engine. If we talk about compressor and turbocharged engines, then there is a forced flow of oxygen. These functions are performed by a compressor or turbocharger. Such engines are characterized by a much higher level of fuel consumption, but at the same time provide more power.

What all engines have in common is that they all take in outside air to burn the fuel and keep the engine running. And since the air comes from the environment, the role of the filter element is extremely important. It is the filter element that traps all dirt, dust and micro-particles, thereby preventing their penetration into the engine and protecting against wear and damage to powertrain components. With operation even large in area filters get clogged with trapped dust and dirt particles. Therefore, air can no longer penetrate through these pores. The more pores are clogged, the less oxygen the engine receives as a result. The less air is needed, the higher is the fuel consumption, the less power is available, the car jerks when moving, during acceleration and at idling speeds jumps are noticed. At the same time the fuel does not burn completely. Such phenomena can easily lead to the flooding of spark plugs. Fuel residue will penetrate into the engine oil. As a result, there is a risk of encountering extremely serious consequences for the incorrect operation of the engine on the car.

Based on all of the above, it is safe to say that the air filter is limited in its lifespan and therefore requires mandatory periodic replacement.

Replacement Interval

It is impossible to say precisely and in relation to all cars, when exactly it is necessary to change the air-cleaning filter. It is largely an individual indicator, which depends on a number of factors.

The first thing to do is to start from the recommendations of the car manufacturer, which regulates the interval of maintenance, and indicates when this or that consumable should be changed. Depending on the car, its year of manufacture, and technical characteristics, the average interval between changes of the air filter is 20 000-30 000 miles. Some people change it every 10 thousand ml, others can easily withstand the exploitation within 40 000 miles. But the regulations are in many respects a conditional reference point. Very often, the regulated terms do not coincide with the real ones, as the air filter gets clogged much earlier and loses its efficiency. It is strongly not recommended to continue exploitation of the car with worn consumables, waiting for the deadline according to the regulations. The element is especially subject to wear and clogging in summer period. During this time, there is an increase in temperature, minimal precipitation, a large amount of dust, sand and other contaminants. All of them enter the underhood space, find themselves in the air intake, and encounter an obstacle in the form of an air filter. Specialists and experienced car owners recommend periodically, especially in summer, to look under the hood, to assess the current condition of the consumable, and if necessary, to replace it. In winter and fall the situation is somewhat different. Wet air and precipitation keep a lot of dust out, which makes the filter work long and efficiently. There is another problem here, though, in the form of moisture, precipitation, and water getting into the consumable. Modern filters are resistant to moisture, but some are not able to withstand direct contact with water. Their capacity drops and the engine suffers from this. The best decision in terms of choosing the interval to replace the air filter is to focus on the characteristic signs of wear and tear. There are several symptoms that indicate that it is time to replace the consumable. Namely:

  • A noticeable drop in the power performance;
  • The driver feels that the car accelerates with difficulty, especially when overtaking;
  • When accelerating you feel a jerk;
  • Fuel consumption increases;
  • Occasional ignition skips appear;
  • The percentage of carbon dioxide in the exhaust increases.

Waiting for all of these symptoms to show up is definitely not a good idea. If you already know your own car well, it will not be difficult for you to understand when the filter is tentatively clogged and begins to gradually lose its effectiveness.

The service life of the consumable is individual for each case. It is influenced not only by operating conditions but also by the design features of the car, the engine used, the condition of the engine itself, as well as the quality of the air intake cleaning element used. Recommendations for the right choice There are several factors that influence the right choice of a suitable air filter for your own car.

There is one key requirement for all such consumables. It lies in the ability to capture foreign debris as efficiently and effectively as possible, ensuring that clean air enters the engine. And in order to filter the air masses, you need to increase the density of the material responsible for delaying contaminants. The denser the paper, the more dirt it will trap.

But at the same time higher density contributes to the detention of airflows, which are necessary for the correct operation of the engine. So it is necessary to increase the density, but only up to certain limits. Because with progressively soiling the resistance of the filter relative to the incoming air grows, the flow capacity will drop. Very dense filters give the cleanest air possible, but they also clog very quickly, wear out and provoke problems with the engine due to lack of oxygen.

Because of this, the leading manufacturers are trying to look for the golden mean between filtration quality and flow capacity. As a result, the best consumables meet roughly the following characteristics: The air resistance in the new filter must average 0.6%. This parameter is stipulated by the design of a particular engine, and it is specified by the manufacturer.

The flow coefficient should not exceed 1%. This means that 99% of all contaminants in the intake air are trapped. The maximum filter resistance should not exceed 50 kPa. A resistance value of 2 kPa is considered normal. At 50 kPa the filter is almost completely clogged, and the oxygen passing into the engine is not enough to burn fuel efficiently. But it is difficult for an ordinary motorist to orientate himself in such figures. They are almost impossible to check on their own. It requires special stands, special skills, etc. That is why car owners are guided more by consumer demands. Such as

  • effective work during the whole declared service life;
  • exact matching of dimensions;
  • good quality of assembly;
  • required number of cleaning stages;
  • reliable construction;
  • quality impregnation with protective compositions;
  • good reputation of the manufacturer, etc.

In order to choose the right air filter for your car, the first thing you need to do is research the owner’s manual.

There, the manufacturer specifies which filters should be used and with what characteristics for this particular engine. All engines are tuned for certain resistance values.

That is why you should not deviate from this criterion, choosing a new expendable. Often, even a concrete brand and catalog number of the filter is specified in the manual. But it is important to understand that we are talking about factory recommended consumables.

We can say that they are the best, because they correspond to the peculiarities of the car exactly. But such parts are usually made under contract with the car company by other companies that specialize namely in consumables. At the same time, this contract manufacturer has similar products, but produced under its own brand. And it costs much cheaper.

No auto company produces its own filters and other consumables. This is a product of other companies, which produce the same air cleaners under the automaker’s brand. Therefore, it often makes sense to save money by buying a supposedly original part, looking through the catalogs of proven and well-established air filter manufacturers.

Original is good, but often too expensive, and for no good reason. What you definitely should not buy is filters of dubious origin from companies about which nobody really knows anything.

The so-called Noname brands are attracted by the low cost of the goods offered. But the installation of such a consumable threatens rapid engine contamination with all the ensuing negative consequences.

Focus on a proven company and a part that meets the requirements of the engine in terms of size, flow capacity, the material of manufacture, etc. All the useful information about the right f specifically for your car can be found in the instruction manual. Don’t chase the most expensive parts, but don’t buy cheap ones either. It’s a filter that you’ll soon have to replace again. But your filter should work efficiently and effectively.


David West
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