Originally Posted By: Kestas
Okay, I can see some cases like that. But all too often I see people give simplistic answers of "annually" when addressing things like changing oil, air filters, and cabin filters. Most of the weight is placed on miles. People should keep maintenance records of their cars, so work can be done on a timely manner. Not evryone drives exactly 15K each year. None of my cars see more than 5K in any year.
Miles or time, miles or time.
Lets use the 2yr/20k example. In two years the filter may be exposed to under 20k miles, sure, but the charcoal element still degrades just by being exposed to air and the filter is still exposed to moisture and organic elements which can degrade it further.
But, factory recommendations cover the lowest common denominator; the best and worst case scenarios are accounted for.
If you inspect your cabin filter and deem it can or should go further, then you are doing your due diligence and making a decision based on your specific circumstances.
The manufacturer nor the members of a message board can make these specific scenario-based recommendations. The "simplistic" answer, as you put it, is the correct answer. Cover the lowest common denominator. Make a safe recommendation.
