Types of Automotive Air FiltersAutomotive air filters have the job of preventing abrasive particles from getting inside engine cylinders where they would then cause oil contamination and undue wear. Most vehicles with fuel injection have pleated paper filters that are in the shape of a flat panel. The filter is generally located inside a plastic box enclosure that is then connected with hose to the throttle body. Older vehicles with carburetors generally have a cylindrical air filter, which is about two to three inches high and with a diameter between six and 16 inches. This type of air filter is found on top of the carburetor in a metal or plastic enclosure. The combination of air filter and enclosure may be referred to as the air cleaner. Paper air filters are by far the most common type of automotive engine air filter. The reason for this is that they're cheap to produce, efficient and easy to clean and/or replace. The paper designation is somewhat misleading, however. Filter media is actually quite different from typical paper that you might use in your printer or for packaging. This type of paper is very porous and also resistant to moisture. Despite what some aftermarket parts advertising implies, paper filters do not restrict engine airflow if they are the appropriate size for the vehicle. The only time they may restrict airflow is if they become significantly clogged. Types of aftermarket air filters include oil-wetted foam, oiled cotton gauze and stainless steel mesh. One of the main uses for foam filters is in off-road or rally conditions as they can trap a large amount of dust without air flow restriction. However, this isn't typically necessary for the average on-road vehicle. The other two types are common in extremely modified engines.
Replacing An Air FilterIf you get your oil changed at a shop, you might be familiar with being told to replace your air filter every time. Even though it's good to check your air filter every oil change, it's usually not necessary to replace an air filter this often. Air filter mileage may vary and your manufacturer's manual should have a recommended interval. If you drive in dusty conditions such as you might find in California, or in a lot of heavy traffic, your air filter may need to be replaced more often. In general though, replacing it every 12 months is usually accurate. Air filters are important parts of your car's engine and keep out a variety of contaminants that can harm your engine and dirty your oil. When the air filter is clean, it gives your engine maximum airflow for the best performance. When it's dirty, it constricts airflow and engine performance may suffer. Think of an air filter like a drain. When drains get clogged, they back up and water runs slowly through them. You may experience the following symptoms when your air filter is dirty:
- Loss of power
- Hard starts
- Reduced gas mileage
- Weak acceleration
- Rough idleFortunately, replacing a car air filter is one of the easiest jobs for even the most amateur mechanic. The filter medium itself is easy to remove from its housing and then the new one can be put in its place. The most involved part is finding the housing and removing the clamps from both the box and the attached hose.
Air Filter FAQ
Q: How often should an air filter be replaced?
A: A common recommendation is every 12,000 miles or 12 months. However, you should check your manual for specifications and check your air filter every oil change to see if it is significantly dirty.
Q: What happens to air filters when they get old?
A: As with any filtration device, air filters begin to break down the longer they're in your car. They also become contaminated with dirt and debris. Once that happens, they're no longer able to function efficiently and you may see a loss of performance as a result.
Q: What's the benefit of replacing an old air filter?
A: If your air filter is dirty, you may start experiencing a loss of engine performance, including less fuel efficiency. Replacing your air filter gives you improved air flow and thus improved performance.
Q: What's involved in an air filter replacement?
A: Most air filters are very simple to replace. If the air filter housing is easy to locate, you simply have to open it, remove the old filter and put the new one in its place. Some modern vehicles have less convenient housings and replacements may be more involved.Visit parts.villaford.com to find a great selection of OEM Ford parts including the Ford Focus air filter. Browse by vehicle or part category, or get more accurate results with a VIN, part number or keyword. It's important to always replace your worn Ford Focus parts with the OEM parts designed for your exact car. Aftermarket parts are made to a generic fit and are not held to the exacting standards of the original. If you have any questions about our parts or need help finding the right one, be sure to contact our Ford parts experts.