I'm contemplating whether or not to retrofit my car with a cold-air intake and performance air filter. Will doing so lower the lifespan of my engine? That is to say, increase likelihood of engine repair, relating to the aforementioned alterations, in the future?

  • What brand air filter will you be using?
    – race fever
    Commented Apr 19, 2016 at 3:45
  • 1
    bought a k&n performance filter ... Commented Apr 19, 2016 at 16:37
  • good choice. make sure to buy the cleaning kit and maintain it properly
    – race fever
    Commented Apr 21, 2016 at 21:36

6 Answers 6


It will have no affect on the longevity of the engine or components as long as you get one with a decent filter on it. You'll have to check reviews on different elements to ensure you are getting one which is good. We'll not mention which ones I think are better, as that gets into the realm of both shopping and opinion. In and of themselves, CAI's will not cause any harm to the vehicle's engine.

  • 2
    Doubling down on the filter! It is very important that you get a good filter like a K&N and do proper maintenance on it. A cheap filter can and will let dirt into the intake. You would be slowly sandblasting your engine's inside. Not good... :)
    – race fever
    Commented Apr 19, 2016 at 3:51

Some people think that a cold air intake will generally improve engine performance, allowing fuel to combust at lower temperatures, increasing fuel efficiency. They believe the lower temperature is actually better for the engine. Performance air filters, if you get a good quality one, might typically allow more air flow while reducing foreign particulate that can enter the engine, so might also help improve engine life.

However, that increase in air flow and lower ignition temperature could potentially provide improved performance, and if you take advantage of that performance by driving more aggressively, then you will negate those benefits and shorten engine life. If you maintain a similar driving style, then the engine will benefit from the change.

  • I highly doubt that putting on a CAI system will make the fuel "combust at lower temperatures". The air temperature difference is a few degrees at best, and the fuel efficiency part isn't really related to combustion temperature as well. Do you have anything to back this up? Commented Apr 19, 2016 at 13:05
  • Could you point out where exactly it mentions combustion temperature? The article is about denser air and lower restriction, which is what the CAI is about. That increases airflow, and if airflow was the choke point - power. What about the fuel combustion, fuel efficiency? The performance air filter improving filtering part is shady as well, tests show that while less restrictive, performance filters usually filter air worse than regular paper filters, which is quite natural. Any arguments? Commented Apr 20, 2016 at 9:29

This very much depends on the type of engine you have. For naturally aspirated engines, these filters should have no effect on longevity.

However, a word of caution, if your car is forced induction (i.e. Turbocharged or Supercharged) not only will the modification have little effect but I have seen instances where the size of particles allowed to pass through the filter can damage the charger.

Particularly susceptible to damage are the G-ladder Supercharger seals fitted to Volkswagen G40 and G60 engines.

If you have a forced induction car, an Intercooler (or larger Intercooler) would be a more suitable modification and yield the kind of returns you would expect from a performance filter on a naturally aspirated car.

Remember, anecdotal evidence gathered on the rolling road by the likes of tuners such as Guy Croft suggests a 1bhp gain for every 2 degrees Celsius lower the intake temperature is (down to about 40 degrees C). Don't do too cold or fuel can start to drop out and ice up in the inlet tract. This is less on an issue for fuel injected cars.

  • the car is a '09 vw gti. Commented Jun 8, 2016 at 16:31
  • An '90 GTI will be forced induction and already will have a turbocharger and intercooler Commented Jun 9, 2016 at 8:35

It's important to get a good cold air intake that actually takes in cold air.

Some kits that call themselves cold air intakes, are actually just exposed underhood pod air filters taking in hot air next to the headers. In a high compression engine that already operates near the detonation(knock) threshold, taking in this heated air can sometimes cause engine damage from detonation.


Cold air intakes can filter down to 50 microns if maintained and cleaned. You can see projected visable light through the small holes of the filter. If it is a daily driver you might want to stick with a regular filter but if it is not the extra flow is worth it.------"The ISO 5011 standard (formerly SAE J726) defines a precise air filter test using precision measurements under controlled conditions. Temperature & humidity of the test dust and air used in the test are strictly monitored and controlled. To obtain an accurate measure of filter efficiency, its very critical to know exactly the amount and size of test dust being fed into the filter during the test. By following the ISO 5011 standards, a filter tested in England can be directly compared to another filter tested in California. The ISO 5011 filter data for each filter is contained in two test reports. Capacity Efficiency and flow restriction.

Without boring you about how the test works, suffice to say they add a controlled amount of dirt to the filter while monitoring its flow capacity. They also monitor the amount of dirt passing through the filter. Various filters were tested being the: AC Delco, Purolator, Baldwin, K&N, and AMSOIL.

Comparing the AC Delco (rated the best from the test results) to the K&N: The AC Delco filter test ran for 60 minutes before reaching its max restriction while the K&N and AMSOIL filters each ran for about 24 minutes before reaching their max restriction. Another interesting bit of information is that the AC Delco accumulated 574 gms of dirt and passed only 0.4 gms. After only 24 minutes the K&N had accumulated 221 gms of dirt but passed 7.0 gms of dirt. Comparing the K&N to the AC Delco the K&N plugged up nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. The AC Delco filter which passed the smallest amount of dirt and had the highest dirt capacity and efficiency but also had the highest relative restriction to flow. Obviously the better filtering media is also the most restrictive".

  • Is there a link for this? I'd be very interested in seeing the results of these tests.
    – Calion
    Commented Jan 27, 2019 at 15:14
  • Is this where you got this information? billswebspace.com/AirFilterTest.htm
    – Calion
    Commented Jan 27, 2019 at 15:39

It can cause damage because if your putting too much air for your fuel injectors to handle, the air fuel ratio will be too lean causing damage to your engine.

  • Maybe you should provide some reasoning as to why a too lean air-fuel ratio will damage an engine. The engine may idle more roughly, it may have less power, but if the air-fuel ratio could damage an engine, I don't see how, but maybe I'm missing something.
    – BillDOe
    Commented Mar 16, 2019 at 19:47
  • Have you heard of the `"lean-burn" engines? worth some time to read about...
    – Solar Mike
    Commented Mar 16, 2019 at 20:05

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