If aftermarket air filters tend to increase the performance of a vehicle, why don't vehicle manufacturers install something similar that is manufactured by themselves in order to increase performance?

Or do these 'performance enhancing' air filters do damage in the long run?


What is the primary purpose and benefit of an air filter?

  • Welcome to the Motor Vehicle Stack Exchange. Nice question. Click on this to see some of the parameters of this particular site. mechanics.stackexchange.com/tour I see that you've also signed up on some of the others sites so you probably know about the badges and what not. Again, welcome to the site! . Cheers! Feb 22, 2016 at 20:02

1 Answer 1


"Performance" at all costs isn't what a manufacturer wants. They want the best, most efficient performance that will still provide the engine a very long lifetime and keep the cost down as much as possible

Some things an aftermarket filter might change:

  • More expensive
  • Requires more maintenance (like an "oiled" K&N Filter)
  • Could increase engine noise
  • For a filter that deletes the air box, you have a higher chance of sucking in water or dirt, and even more sound increase
  • I guess increased air flow could change fuel economy (guessing for sure)

What is an air filter for?

To provide clean air to the engine of course. The air box (filter housing) on most cars also provide some safeguards for sucking in water in the form of large splashes from puddles, but the filters only real job is to keep small particles out of the engine, and to not restrict the air flow too much while doing it.

  • 2
    I just noticed this question was tagged as motorcycle. In that case the sound can change quite a bit because you're leaning right over the air box, and also, noise levels are important for motorcycle regulations.
    – JPhi1618
    Feb 22, 2016 at 21:06
  • 2
    Worth noting that oiled filters can damage some airflow sensors. Also for the extreme of performance / lifespan tradeoff look at some race cars / dragsters etc. that run no air filtration at all - saves weight & restriction at the price of rebuilding or replacing the engine every race or three - something they likely expect to do anyway. Top fuel drag racers especially treat engines as a consumable item, surviving only a few runs at most.
    – John U
    Feb 23, 2016 at 18:33

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .