If your vehicle is less than 10 years old, there’s a good chance it has two air filters. Most people are aware of the engine air filter, but not the cabin air filter for the passenger compartment.
A vehicle’s engine should be kept as clean as possible and is equipped with air, oil, and gas filters for this purpose (although gas filters are becoming less and less common). Filters help the engine run smoothly, and manufacturers recommend replacing them at regular intervals of time or kilometres travelled. Filters have proven benefits, and conscientious drivers should be sure to have them inspected or replaced when their normal life cycle has been reached.
Engine air filter
The engine air filter is usually installed in a large box in the middle of an air circulation system that directs air from the front grill of the engine bay to the intake.
It needs to be inspected but not necessarily replaced every time you get your oil changed. The filter’s condition depends on the kinds of roads you drive on, the time of year, and how many kilometres you’ve travelled. The technician will let you know if it needs to be replaced. Made of compressed fibres, the embossed filter membrane will break and become less effective if air is blown on it to clean it.
Cabin air filter
Usually installed under the dashboard or in the glove compartment, the cabin air filter protects against dust, pollen, and mildew. With air conditioning systems, insulation, and rubber installed on car doors, plus the fact that we roll down the windows less and less, the passenger compartment is increasingly becoming an airtight, enclosed space—hence the need to filter the air for the passengers’ well-being. Cabin air filters provide average protection against air pollution, with a rating of MERV 8* (compared to MERV 20 for a hospital operating room!). They’re generally square-shaped and inexpensive.
*The MERV rating (standing for “Minimum Efficiency Reporting Value”) is a measurement scale to rate filter efficiency.