How to choose a fuel filter for your car?

How To

Which fuel filter is better to choose? The answer to this question depends on many factors: the type of car engine and the fuel it uses, the fineness of the sieve, the quality of filter manufacturing, the manufacturer’s firm. In this article we will tell you what to pay attention to when choosing a fuel filter. Read more: How do I choose an air filter for my car?

Fuel Filter Functions

Any fuel filter is designed to clean fuel (gasoline, diesel, gas) from solid particles of dirt, some moisture, paraffin (for diesel). It is necessary to protect the elements of the fuel system of the car. It provides not only its normal operation, but also extends the service life of the entire fuel system as a whole.

A fuel filter is an expandable element, which cannot be repaired after a failure, and you must periodically replace it in any case, no matter how expensive it is.

Signs of filter pollution

Many motorists are interested in the question, if the fuel filter is clogged, what are the symptoms? And here, regardless of the type of engine, there are a number of common signs, the presence of which can be used to judge that the fuel filter is completely or partially out of order. However, it is worth mentioning that the following signs may also indicate other breakdowns in the car.

So, the signs of its clogging are:

  • The power of the engine decreases. And when working in all modes – when accelerating, when driving uphill, when carrying cargo. Feelings for the driver are similar to those, when the engine “trots”. These phenomena are caused by insufficient quantity of fuel in the air-fuel mixture.
  • Increased fuel consumption
  • “Floating” values of idle speed. RPMs, as a rule, decrease for no reason until the engine stops completely.
  • The engine does not start. This is possible in the most “started” case, when the filter is critically clogged and is not passing through the amount of fuel needed to run the engine.

Some cars have an indicator directly on the dashboard or screen informing the driver that the fuel filter needs to be changed. Note that a clogged filter element greatly increases the load on the fuel pump. It begins to work “to the wear and tear”, and this reduces its overall life and threatens to fail. It also concerns diesel high-pressure pumps (HPP). If the fuel filter is clogged, the injectors are also clogged, both gasoline and diesel.

At what mileage should I change the fuel filter?

All automobile manufacturers clearly specify at what mileage, or after what time it is necessary to change the fuel filter according to the regulations.

Typically, the mileage is about 30-60 thousand miles or once every two years (whichever comes first). The exact values depend on the specific make of car and should be further clarified in the technical documentation (manual) of the car.

If the filter is clogged before the scheduled replacement, it must be changed unscheduled. It is especially urgent in case the fuel in the tank is of dubious quality.


What are the fuel filters?

To determine the answer to the question, what fuel filter to choose, it makes sense to know the possible types. After all, depending on the fuel system and the filter make different, with different degree of filtration. So, they come in:

Injector filters. Injection gasoline engines are mounted into the gas tank or just after it outside. They have better filtration capacity compared to carburetor ones. Thus, with their help, particles of dirt with a size of 10 microns and more (also depends on the particular filter) are sifted out. It is important that such filters can operate at a pressure of about 3…4 bar.

As for their filtration degree, it depends on the injection system:

  • distributive injection – 25…65% for particles 3…5 microns;
  • traditional direct injection systems – 48…70% for particles 3…5 μm;
  • the newest direct injection systems – 85…95% for particles 3…5 μm.

Diesel. The most complex fuel filters, because their tasks include sifting out not only dirt particles, but also water and paraffin.

A modern 2 micron fuel filter should screen out as the hardware is more precise and works under more pressure. Pay attention that if the old (“classic”) diesel systems worked at a pressure up to 2000 bar, the modern Common Rail systems develop pressure up to 2500 bar. Accordingly, the fuel filters must be designed to work with it.

Similarly, for diesel filters, a filtration gradation is assumed:

  • for classic old-style engines – 25…65% for particles of 3…5 microns;
  • for classic Common Rail systems – 85…95% for particles 3…5 microns;
  • for the newest Common Rail systems – 98% for particles of 2 microns (the so-called fuel filters of 2 microns).

Regardless of the type of fuel filter, they must filter up to 95% of the moisture present in the fuel. In reality, many of the values quoted are exaggerations, and few manufacturers are able to produce filters with such high performance.

However, the device type is the first, but not the only criterion for determining which fuel filter is best.

Filter selection criteria

In addition to dividing them by engine type, filters are also differentiated according to their cutoff fineness. This index is expressed as a percentage and clearly indicates how much debris the filter can catch. There are three types of sieve fineness:

  1. Medium. Filters screen 50% of the particles of the size they are designed for.
  2. Nominal. Similarly, screen out 95% of particles.
  3. Absolute. Similarly, 100%.

In practice, the manufacturer on the product packaging explicitly states that, for example, “the nominal sieve fineness is 10 microns”. This means that this fuel filter is able to sieve 95% of the particles with a size of 10 microns or more.

The next important factor when you don’t know which fuel filter to buy is the quality of the product. So, you need to carefully inspect:

  1. The quality of the paper. Unfortunately, it is almost impossible to visually determine this factor (especially if it is not an insert and sealed flask of metal or plastic). But when you have the opportunity, try the paper to the touch. When the paper is of low quality, there is a high probability that small lint will separate from the filter element, which will later get into the fuel system. And if for carburetor engines it is not so terrible, but for injector engines, and even more so for diesel engines – very critical.
  2. Winding density. This can be determined visually or by touch. So, if the manufacturer has spared on the material, and used not enough paper in the filter (that is, the density of the winding is low), then the degree of filtration will also be insufficient. It is desirable to buy filters with sufficient density of the filter element.
  3. Rapid failure of the filter. In particular, in some cases, it is noted that the filter is quickly clogged with large particles of dirt from the fuel. If it occurs over the whole area of the filter element, you should stop using low-quality gasoline or diesel fuel. If clogging occurs only in one area – it is an indication of a poor quality filter element.

A very important issue when choosing a particular filter is its height. The insert (cartridge) must be tightly sealed in the “cup” (seat). A small backlash of even 5 mm in the long term can lead to severe consequences, up to complete failure of the nozzles. Very often when you open the sealed fuel filters it turned out that the filter element wasn’t finished.

And, of course, one of the most important questions is, what company fuel filter to buy the best? After all, products of different brands differ not only in price, but also in performance and features of use.

Fuel Filters Overview
The following is a list of popular brands that produce fuel filters for gasoline and diesel engines. The rating does not advertise any of the brands presented in it, but is created only on the basis of car enthusiasts’ reviews. Below are the fuel filters that are better for diesel and gasoline engines.

K&N fuel filters

American company K&N is a leader in automotive filtration and technology, offering products for protection and durability in vehicles. In addition to air filters, K&N® makes many other products: air intake systems, oil filters, fuel filters, cabin air filters and home air filters.

FRAM fuel filters

The Cleveland, Ohio based company is the leading supplier of oil filters in the United States. Today, FRAM is known as America’s number one oil filter brand, and the FRAM team continues to produce and sell a variety of quality oil, air and fuel filters, as well as many automotive accessories such as PCV valves, crankcase filters, and transmission modulators.

The company has North American research and development, manufacturing and sales centers in Rochester Hills, Michigan; Hebron, Kentucky; and Greenville, Ohio. To ensure that products are produced on time and meet stringent internal and customer requirements, FRAM uses state-of-the-art process control and automated inspection equipment.

MANN fuel filters

Mann-Filter fuel filters are produced by the German company FilterwerkMann+Hummel GmbH, which is one of the largest manufacturers of filter elements in the European Union. Filters are supplied as original parts for vehicles made by Mercedes-Benz, BMW, Volkswagen, Audi, Opel, Ford, Volvo, Saab, Nissan, Citroen, RENAULT, Peugeot, Fiat, Seat, Komatsu, Caterpillar, Iveco, Rolls-royce, Porsche, Jaguar, Lombargini and others.

Numerous reviews and tests conducted by initiative car enthusiasts show that Mann brand filters are really one of the best solutions for modern engines. They ensure long life even when using low-quality domestic fuel. The paper is very dense, and the workmanship is top-notch.

BOSCH fuel filters

Under the brand name BOSCH, high-quality fuel filters for diesel and gasoline engines are also produced. It should be noted that the BOSCH package often includes Mann-Filter products. But the quality of these filters is slightly inferior to those made by MANN. Tests, including with the removal of sealed cartridges, fuel filters “Bosch” showed that inside there is a quality filter element, which has a sufficient amount of dense paper in the base and declared in the documentation.

WIX fuel filters

WIX fuel filters are produced by the company of the same name, whose production facilities are located in Poland. WIX is one of the largest manufacturers of different filters. In particular, its products are used by such automakers as Ford, Volkswagen, Seat, GM, Fiat, LandRover and others.

WIX fuel filters are of high quality filter elements, which can be installed on almost any car (in accordance with the size and other parameters). The advantage of the brand is a wide range of produced filters.

Mahle fuel filters

Mahle fuel filters are among the most qualitative and popular in its segment of the market. Such filters are installed not only on cars, but also on commercial vehicles. For example, this brand filters for Volkswagen cars are installed as the original ones. The company has offices and production facilities in different parts of the world – in Europe, America and Asia. Therefore, for different cars the country of manufacture can be different.

Delphi fuel filters

Delphi has offices and production facilities in 33 countries around the world. Accordingly, the fuel filters may be produced in different states. It is noted that it is better to install Delphi filters on the fuel system of a similar brand. This will ensure maximum cleaning and normal operation of the system and the entire engine as a whole. The Delphi line of fuel filters has samples for installation on cars, SUVs and trucks. The range is very wide.

UFI fuel filters

UFI manufactures a variety of filter elements, including fuel filters under its own brand. Most of the production facilities are located in Italy, but there are branches in other European countries, as well as in the U.S. UFI filters are of very high quality and reliability. Proof of this is the use of filters of the brand in the sports bolides Ferrari, participating in the races “Formula 1”. Like all the previous car manufacturers often use the filters of this company as the original equipment for their cars.


The fuel filter should be chosen first and foremost based on the requirements of the car manufacturer of your car. The documentation clearly spells out the technical parameters, including the dimensions that the filter must meet. The second important parameter is the brand of the filter itself. The best option in this case would be to buy a fuel filter original or an analogue from the middle or high price range.

Avoid cheap filters, they are known to be of poor quality! And what fuel filter do you install in your car? Share this information in the comments.

David West
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