Everything You Should Know About Oil Filters MILTA Technology

Everything You Should Know About Oil Filters

Every car and just about every engine out there has an oil filter. This apparently inconspicuous filter is about the size of a tin can and yet plays an incredibly important role and a supporting function when it comes to the proper functioning of the engine. We often emphasize how important it is to know what makes your car “tick”. Knowing why you have and why you should regularly replace your engine oil filter is definitely one of those things every car owner should know.

What does an oil filter do?

Depending on the size of the engine, an oil pump pumps several hundred litres (yes, this is correct) of oil per minute through the oil circuit. The oil filter is responsible for keeping the engine oil clean. In doing so, it plays an important role.

To keep the engine oil clean, the oil filter sifts out any physical particles that enter the oil during the combustion process. This can include:

  • Dirt
  • Dust
  • Sludge and soot
  • Metal debris

By capturing and removing these unwanted particles out of the system, it prevents them from circulating through the engine and cause damage.

Why do you need an oil filter change?

As we mentioned before, an oil filter removes and captures damaging physical particles from the oil. Once the oil filter is full, this process stops and those damaging particles enter the oil circuit. As time goes by, those particles will cause damage. If you are “lucky”, you might even experience the worst-case scenario. The particles that were previously caught by the media of your oil filter might detach and join the rest of the particles that are freely passing through your old oil filter.

Trust us, replacing an oil filter is much cheaper and easier than fixing a damaged engine.

When should you replace your oil filter?

Your engine oil filter should be replaced at every oil change interval. Depending on the length of the oil change interval, the oil filter should be compliant. This means that in the case of extended oil change intervals we see on some modern vehicles, you should not try to save money on a cheap oil filter that won’t be able to clean the oil for an extended period of time.

How do engine oil filters work?

Both screw-on filters and filter inserts use some sort of filter media. Filter media is an expression for the ribbed material that actually does the oil filtering. The filter media themselves are made out of cellulose (as a base material) and/or polyester. Polyester improves the efficiency as well as the dust absorption in oil filtration. In addition, more and more fully synthetic media are being used by the industry. They are basically temperature and water-resistant.

With the help of fully synthetic polyester media, the increasing requirements of vehicle manufacturers (OEM) can be better met and the filtration performance can be more precise. This applies above all to the required chemical resistance and temperature resistance. As a result, a good oil filter is made up of a mix of different layers and materials. The longer the oil change intervals, the more important the quality of the oil filter. In principle, an automotive professional should always use branded products with clear identification! There are many oil filter counterfeits on the market so make sure your mechanic is always using high-quality replacement oil filters.

Different designs of oil filters

Screw-on filters

Screw-on filters, or as they are often called “spin-on filters”, consist of a metal housing and an internal filter element. The internal filter element is supported by a frame made out of perforated sheet metal. The screw-on filter is screwed onto the engine block and simply exchanged. The housing of a screw-on filter features a sealing ring that must be lubricated with a little oil before it is mounted. This prevents oil from escaping and leaking. Screw-on filters can be used for both main flow and bypass flow filtration.

Oil filter inserts (cartridge construction)

Vehicles with a cartridge oil filter construction have a reusable, lifetime filter housing that is screwed to the engine block. The oil filter itself can be replaced separately. The filter insert consists of two temperature-resistant, glued or welded thermoplastic end caps with an intermediate filter medium. Modern branded
filter elements have metal-free components and are thermally usable. This means that, unlike screw-on filters (with a metal housing), the filter element can be burned without leaving any residue.


Let’s recap; the oil filter is an essential part of your engine. It makes sure your engine is lubricated by a clean stream of oil which in return prevents damage and ensures a smooth driving experience. If you buy auto parts yourself, make sure you aren’t going for the cheapest oil filters on the market. High-quality oil filters are not significantly more expensive and they are definitely worth the money.

We recommend you replace your engine oil filter with every oil change. Some people and even mechanics will say there is nothing wrong with changing the oil filter at every other oil change. Trust us, it isn’t worth taking the risk. Make sure your mechanic is using high-quality oil filters that are suitable for the length of your oil change interval.

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