Your Engine's Air Filter

Your air filter is one of the most important parts of your engine. For each gallon of fuel burned, up to 10,000 gallons of air is required for your engine to function properly. If your car consumes 40 gallons of fuel each month, it is also consuming approximately 400,000 gallons of air. That is equivalent to the amount of water in a five feet deep, 28×10 feet swimming pool. That is a lot of air traveling through your engine, and roadside air contains contaminants such as dust, dirt, soot, and bugs that must be filtered out.

A gasoline engine requires three elements to function properly: air, fuel, and spark. If you reduce or contaminate any of these three components, your engine will lose performance, fuel economy, and will also develop drivability issues. Additionally, if the air entering the engine is dirty, the life expectancy of the engine is greatly reduced.

The sole job of the engine air filter is to keep the air entering the engine clean and unrestricted. The air filter is located between the fresh air inlet and the engine itself. It sits inside an air box where a lid seals the filter between the upper air box and the lower air box. This forces the air to come through the fresh air inlet and through the air filter before it reaches the intake manifold and creates an air and fuel mixture in the combustion chamber.

The engine air filter is one of the easiest parts to replace, yet it is also one of the most neglected and forgotten components. Your engine air filter might be a seemingly low tech item, but it's in charge of keeping an unrestricted steady stream of clean air flowing through your engine.

It is a good idea to remove and inspect the engine air filter every time you change your engine oil, or at least twice a year. Once the air filter is removed, it should be inspected for tears, cuts, holes, excessive dirt and debris, and rubber sealing surface flaws.

The color of your air filter may indicate that your filter needs to be replaced. The color of most new air filters is white or very light yellow or creme colored. A black or dark brown filter may not allow sufficient air into your engine and could starve the vehicle of power, resulting in poor fuel economy. If there is anything unusual about the physical condition of your air filter, don't take any risks. Replace the air filter with a new OE quality filter right away.

The quality of the engine air filter you choose is important. The quality of replacement filters should be at least the quality of the filter originally installed by the manufacturer. The air filter needs to have a capacity high enough to contain normal dirt accumulation before air flow is restricted and also be efficient at capturing tiny dirt and debris particles to prevent them from entering the engine combustion chamber. The goal is to choose a filter that provides the best balance between capturing contaminants and not restricting air flow.

Some amount of dirt and debris on an air filter is normal and is accounted for in the capacity design of the filter. Normal amounts of dirt and debris should not restrict the air flow. A rule of thumb is that a good quality air filter should last between 15,000-30,000 miles depending on driving conditions. The condition of the air filter is subjective, but it can be accurately determined by an experienced automotive technician. In some cases, the life of an air filter can be prolonged by using compressed air to blow dirt and debris out of the filter.

Be mindful of your engine air filter and have it replaced regularly, as needed. Staying current on the maintenance of your engine air filter is a simple and inexpensive way to keep your engine running efficiently, and to keep your vehicle on the road for a long time.