I'm in a dusty area and have 24k miles on my car. I checked the filter and changed it even tho it looked like it could go another 12k miles. I keep the A/C and heater on recycle 98% of the time and that could be the reason it wasn't all that dirty. Price was $48.50 plus $27.50 for the dealer to change it. Did it myself and saved a few $$$. It was a little tricky but it will be easier after you do it the first time.