Every car owner who has taken their car in for an oil change has been told that their engine air filter's dirty.
Here's what goes into the determination of when to change the filter: First, your owner's manual will have a recommendation of when to change the filter. Second, a visual inspection by your technician may determine that your filter it is visibly dirty and needs to be changed.
So between your owner's manual and your technician's inspection there's really no guesswork involved.
Now, most air filters purchased in , , or don't cost a lot to replace. It's just that people hate getting caught with an unexpected expense. On the plus side, though, changing a dirty air filter at can often save enough on gas to pay for itself before your next oil change in .
Think about a dirty furnace filter in your home. When it's all clogged up, enough clean air can't get through. In your , that means that your engine can't get as much air as it needs to burn the fuel efficiently. So it makes do with less air and has to use more expensive gas to move your vehicle around roads.
Your actually needs about 12,000 gallons of air for every gallon of gas it burns. Engine air filters don't cost much in at . When it's time to change yours, just get it done. You'll buy less fuel, have better performance and protect your engine.