Air Filter Tips
Check and/or change your Air Filter every "Oil & Filter Service" to improve fuel economy and keep your engine running smoothly.
It's hard to give a specific time or mileage figure because the life of the filter depends on how much crud it ingests. A filter that lasts 20,000 or even 30,000 miles on a vehicle that's driven mostly on expressways may last only a few months in a rural setting where the vehicle is driven frequently on dirt roads. Changing it annually or every 15,000 miles for preventative maintenance may be a good recommendation for the city driver, but not its country cousin.
Regardless of the mileage or time, a filter should be replaced before it reaches the point where it creates a significant restriction to airflow. But when exactly that point is reached is subject to opinion. Fuel economy, performance and emissions begin to deteriorate and get progressively worse until the dirty filter is replaced.