What are the recommendations for changing filters?

It is best to follow the Severe Service maintenance schedules found in most new car owner’s manuals, with a few exceptions:

AIR FILTERS need to be inspected regularly and replaced as often as needed, regardless of mileage or time. Dirty air filters can increase fuel consumption and exhaust emissions.

FUEL FILTERS should be replaced yearly and/or at every tune-up, especially on fuel injected cars. The fuel filter in a vehicle with electronic fuel injection passes a much larger volume of fuel than its counterpart in a carbureted application. If the tank is dirty or rusty, constant fuel recirculation can pick up a lot of debris that ends up in the filter. If the filter plugs, the engine is starved for fuel or unfiltered fuel is allowed to bypass the filter. The latter can damage injectors.

OIL FILTERS need to be replaced at every oil change (every six months or 3,000 miles in most cases) despite the advice in many owner’s manuals to only change the filter at every other oil change. A new filter is cheap insurance against major engine damage, so why take unnecessary risks?

Few owner’s manuals have a suggested change interval for the automatic transmission fluid (ATF) or fluid filter unless the vehicle is used for towing. Most transmission specialists say the best preventative maintenance for prolonging automatic transmission life is to change fluid and filter every two years or 30,000 miles.

Follow the manufacturer’s recommendations on the specific type of ATF to use. The type of ATF should match the specs required for the application.