The engine air filter is designed for your vehicle and is intended to only let filtered air pass through to the engine. If the wrong size filter is used, unfiltered air can slip through the opening, resulting in dirt accumulating on the mass air flow sensor. This can cause the engine light to come on, as the engine can no longer determine how much fuel it needs to mix for proper combustion. Using an incorrectly sized air filter won't necessarily damage the air conditioning system, but it can reduce its efficiency and lead to an increase in your utility bill.
Additionally, a dirty or shabby air filter restricts air flow and reduces oxygen in the mixture, causing the engine to consume more fuel in order to generate enough power. A clean, properly installed air filter improves fuel economy, extends engine life, reduces emissions, and boosts acceleration. It's important to note that using an air filter with a higher MERV (minimum efficiency reporting value) rating isn't necessarily the best option. Most manufacturers recommend replacing the air filter every 12,000 miles (approximately 19,000 km) or every 12 months, whichever comes first.
If you live in an agricultural area or any area with a lot of dust or impurities in the air, you should consider changing your air filter more often. If you hear unusual noises coming from your car, particularly when coughing, bursting or spitting, it means that the engine is not getting enough air flow and that the air filter needs to be replaced. Regardless of the type that is best for your individual climate system, it's essential that you change or clean your air filter regularly.
