Jones Junction discusses when to replace an air filter

Jones Junction discusses how to tell if a car's air filter is bad and when to replace an air filter.

An air filter in good shape enhances gas mileage, lowers emissions and may even prolong the engine's life, a posting on the Jones Junction website said. 

Signs indicating an air filter that is past its prime include the following:

- If fuel economy decreases, it could be a dirty air filter. Although other things such as tire pressure can affect your car's mileage, check the air filter if you feel the vehicle isn't getting the mileage it used to. It should look clean if it is in good shape.  

- If your car doesn't accelerate as good as it should, it could be a dirty air filter. Vehicles need clean air for proper acceleration.

- If the vehicle smells of gas when you start it, this could mean there isn't enough oxygen in the carburetor. A gas smell could mean a dirty air filter.

- If the engine makes sputtering noises, especially when a car is idling, such as at a red light, this could be an air filter issue.