If you're driving around with a dirty air filter you're losing power from your engine and burning more gas – and you don't want either of those. A clean filter lets your engine breathe so it can work at peak performance, deliver all of its horsepower and reduce your fuel consumption. At a result, you should change air filter paper on time.
Expert says that gas turbine filter media need only be changed every 12,000 miles but it recommends cleaning them sooner if they get dirty. This will depend on the conditions where you live and drive because dust and sand from trails and country roads will clog up an air filter much quicker that the highway.