Jaquan Green

Knowing how often to replace the air filter in a car is crucial in safeguarding the engine and maintaining its optimal performance for years to come.

In an internal combustion engine, just as with humans, clean air is essential. The engine air filter, different from the cabin air filter, blocks solid pollutants from entering the engine. If the air filter is dirty, it can trigger the Check Engine Light and cause a range of performance issues. Never operate a car without an air filter ($25) installed, as minute particles of dirt and rust from the air cleaner housing can infiltrate the engine’s combustion chamber, leading to damage of the main bearings and crankshaft and potentially ruin a $4,000 engine in no time.

An engine air filter is a device typically made of pleated, solvent-treated pulp paper that traps harmful contaminants in the air, with some featuring a stainless-steel grid backing that enhances the filter’s rigidity, preventing premature seal failure. It not only purifies the air but also helps extinguish flames if an engine backfires.

Replacing the engine air filter is vital as it provides better fuel economy, maintains the optimum air-to-fuel ratio, improves acceleration and performance by allowing maximum air entry into the combustion chamber, increases mass air flow (MAF) sensor accuracy, reduces tailpipe emissions, and extends the engine’s lifespan by preventing the smallest grit from penetrating the engine, which can cause expensive engine parts to wear out prematurely.

Typically, most manufacturers recommend replacing the engine air filter every two years or 30,000 miles under standard driving conditions, although the frequency of replacement depends on driving conditions. Check the air filter every 12,000 miles or at each oil change, lightly tapping it on the ground to shake off any loose dirt. Use the “light” test, shining a flashlight or trouble light through the backside of the filter. If the glow is visible, the filter is still okay. Use common sense when evaluating the filter’s condition; if the filter looks discolored, the seal is weak, or the paper/media has dried out, it should be replaced.
To ensure optimal engine performance, it is important to replace the air filter at least once a year, or sooner under certain conditions, such as frequent stop-and-go driving, idling for long periods, or driving in extremely dusty, sandy, or hot/cold weather conditions. If opting for professional replacement, the cost can range from $25 to $50 for labor and the marked-up price of the filter. A reputable shop may add an additional $10 to $30 to the retail price of the filter but stands by their work. Alternatively, replacing the air filter yourself is an easy task, but make sure to purchase a quality replacement filter with a polyurethane frame to ensure a tight seal between the filter and its housing. When shopping for air filters, be aware that manufacturer-branded parts can be more expensive than subsidiary-branded parts, even if they are the exact same product. It is also important to vacuum any grit build-up around the air filter housing and avoid using compressed air to blow gunk out of the air filter housing, which can spread dirt all over the engine compartment.