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Importance of Filters

10 Aug 2020


Keeping a vehicle running clean is the job of the four main filters – air, cabin, oil and fuel. They are key to protecting parts of the vehicle and the passenger from harm. Therefore, it is important that they are changed regularly.

Air Filters

The role of the air filter is to reduce airborne contaminants such as dust, pollen and other dirt particles being sucked into the engine, and thereby increasing the damage to engine parts such as piston rings, bushings and cylinders.

Cleaner air also helps engine performance increasing torque and aiding fuel consumption. A dirty or blocked air filter restricts the air flowing into the vehicle’s engine, causing it to work harder and therefore burn more fuel.

Reasons for Product Failure/Replacement

Signs of a dirty air filter include a misfiring engine, unusual noises and reduced fuel economy. An air filter is normally yellow/white in colour so if it is brown or black or oily, it needs changing.

The benefits of NAPA air filters are:

  • The polyurethane mix seals allow elasticity and resistance to compression at extremely high temperatures, so even in difficult operating conditions, they remain airtight.
  • The filter media, based on cellulose or synthetic fibres ensures 99.9% filtration efficiency for particles of a few microns, and is matched to the criteria set by the vehicle manufacturer.
  • To stop the air pleats sticking together during use, NAPA filters are stabilised by special ribs, and with their even distribution, filtration can occur across the entire surface, maximising cleaning efficiency.
  • The filter media is also F1 or S1 flammability class, so any fire self-extinguishes, reducing the spread. In the event of air-supply system sucking in (for example) the ignition source, passengers are protected.

Cabin Filters

Cabin or pollen filters perform a similar role to air filters except they decontaminate the air coming into the cockpit or cabin, removing airborne contaminants such as dust, pollen, leaves and bugs, helping to keep heating and air systems clear.

This provides comfort to passengers, protecting against hay fever, eye irritation and ensure the driver’s concentration levels are not affected.

Reasons for Product Failure/Replacement

Ideally cabin filters should be checked every year, and replaced every two, but owner’s manuals often stated every 15,000 to 25,000 miles so it depends how you drive.

A common symptom of a dirty cabin filter is poor airflow from the vehicle’s interior vents, bad odours and misting windscreens. If the filter is less efficient, more energy from the heater fan unit is required to circulate the air around the vehicle.

Charcoal or carbon filters have the added benefit of trapping dust and debris, as well as absorbing fumes and odours.

The benefits of NAPA cabin filters are:

  • The media stop particles as small as 1 micron, 70 times smaller than the thickness of a human hair ensure that most pollutants are trapped in the cabin filter.
  • The charcoal or cabin filters binds harmful gaseous particles and reduces unpleasant odours for passengers. The amount of carbon used is calculated to effectively purify the air from harmful volatile organic compounds for a long period of time.

Fuel Filters

For the reliable operation of the engine, correct fuel filtration is key. Fuel impurity affects the wear of the engine parts such as injectors, pumps and fuel-pressure values.

Reasons for Product Failure/Replacement

Any fuel entering a vehicle goes through a filter, removing any dirt or rust or water partials carried from petrol stations or distribution channels, or from the engine itself. Such contaminants can plug fuel injectors and carburettors, causing engine malfunction and damage.

The benefits of NAPA fuel filters are:

  • They remove rust particles, metal filings, plus water (in diesel engines) as well as impurities in the fuel itself.
  • They use filter media that is suitable for the requirements of the engine or vehicle manufacturer, which is tested thoroughly for their efficiency and properties.
  • For diesel engines injection systems, which require very efficient filtration and water separation, there are filter solutions to support.
  • Any leak in fuel poses a threat of fire, so all seals go through stringent and extensive testing to ensure they are strong.

Oil Filters

Oil filters help to remove contaminants from the vehicle’s engine oil and keep the engine clean. If oil becomes unfiltered, it can become saturated with hard particles that can wear the surfaces of the engine, causing damage.

Reasons for Product Failure/Replacement

Car manufacturers suggest changing the filters alongside each oil change. If the engine starts to show low or high oil pressure, is overheating or declining in performance this is a sign that the filter needs changing. Dirty exhaust fumes and low oil pressure is also an indicator.

The benefits of NAPA oil filters are:

  • The valves in the spin-on oil filters match the individual requirements of the engine or vehicle manufacturer to ensure the filter functions effectively in the oil system.
  • The trend in filtration to replace metal parts for plastic to reduce the mass of the filter and aid its disposal is reflected in the NAPA range.
  • The filter media, valves, springs, housing and other elements are subject to regular laboratory control tests to ensure high quality standards are maintained.

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