Engine air filter is a periodic maintenance part, and replacement schedule varies from brand and model. For example, the recommended schedule is every 45,000 miles for most Chevrolet cars where Ford recommends every 30,000 on its most models. Hyundai recommends every 30,000 miles, but 15,000 miles for critical driving conditions such extreme weather, frequent stop and go driving, or dusty road.
You can obtain if a filter needs replacement by doing a visual inspection. The air filter is easy to access in most engines, and you can know the location by checking your owner’s manual. A damaged or malfunctioned filter triggers several warning signs. If you know them, then you can easily understand whether you should replace it or not before the scheduled maintenance.
If you can’t determine by a visual inspection, but if it’s more than the mileage recommended by your maker, you should replace the air filter no matter what it is working or not. It’s better to check the car by a professional if you think your filter isn’t working properly.
A blocked or clogged air filter won’t reduce fuel efficiency significantly, but it can decrease the acceleration up to 6% to 11%. Acceleration is hard to measure than fuel efficiency or gas mileage, so you may or may not notice a performance loss. That’s why it’s wise to change the air filter by the manufacturer’s recommended interval.