Even drivers who know very little about the inner workings of their vehicles usually know the basics of preventive maintenance. They know their oil should be replaced regularly, their tires should be inflated to the correct pressure and they should heed any warning lights that illuminate on their dashboards to alert them of potential problems. Beyond that cursory knowledge, many drivers have an “if it isn't broke, don’t fix it” mentality about their cars. Sooner or later, these drivers usually find out the hard way why that’s not always a smart mindset. One small and inexpensive item that ranks high on the neglected car-care list are the air filters.