For high mileage vehicles, replacing the fuel filter annually for preventative maintenance is a good idea for two reasons. By the time a vehicle is six or seven years old, there can be a fair amount of rust and debris in the fuel tank. Rust can be formed by moisture and condensation, and debris can get into your tank anytime you add fuel. So changing it on a periodic basis can help minimize the risk of plugging. Most newer vehicles do not have a specified interval for replacing the fuel filter. In fact, some even have "lifetime" filters that supposedly never need to be changed. But any filter can plug up if enough rust or debris gets sucked into the fuel inlet. Gasoline is supposed to be filtered at the pump. But it sometimes isn’t. What’s more, the fuel you put in your tank may be contaminated with water from leaky underground storage tanks, improperly mixed alcohol blends, or even watered-down by an unscrupulous operator who’s trying to make a fast buck. So there are no guarantees. Replacing the filter periodically for preventative maintenance is simply insurance that reduces the risk of it plugging up. Given enough time, every filter will eventually reach the end of its service life. Even the filter in a brand new vehicle right off the showroom floor is at risk if the owner happens to get a dirty tank of fuel. Filter Inspection If you don’t want to replace the filter unnecessarily, you can remove it and check it to see if it passes air easily (More information on replacing fuel filtersis available). If the filter creates any significant resistance when you blow through it, it needs to be replaced.