As a general rule, most drivers should be able to go a year or two before needing to replace their engine air filter. The recommended average length of service is approximately 10,000 to 15,000 miles, which for most people is approximately every year. However, this is just a recommendation and doesn't take into account individual driving situations. If you have a lot of stop-and-start driving, your air filter will get dirty faster and cause your engine to malfunction.
You may notice less power and weaker acceleration, which is a sign that your engine is not receiving the right amount of air and oxygen. Most cars have the cabin air filter placed behind the glove compartment or under the dashboard. If you drive with a lot of traffic on a regular basis, your air filter won't last as long. You can visually check the engine air filter to see if it looks dirty or if it is full of debris.
If you've recently noticed that you need to refill your gas tank more often than usual, it's probably time to check your air filter. Other signs that the air filter is affecting the performance of your car are sudden movements when accelerating or not responding as well as it should. A good indication that the air filter needs to be replaced is the presence of black smoke coming from the exhaust pipes when you start the engine. Air filter replacement can be part of a general tuning service that will help you get better mileage and performance out of your vehicle.
One of the most common problems you'll encounter when you need to change your engine's air filter is decreased fuel consumption. When the engine air filter is dirty, air cannot pass through the filter to the engine, affecting the car's entire emission control system. Over time, as dust and dirt build up, the air filter will darken and dirt will be noticeable. Some manufacturers of newer car models have changed the engine design to make more efficient use of space, and sometimes that means placing air filters in more difficult to reach places, which can slow down the process.