K&N air filters do they really work?

I have three favorite reasons for believing a K&N air filter really works:

  1.  Nothing to throw away, just clean and recycle.
  2. I can clean it as often as I want. It’s like having a new filter whenever I want one – for free!
  3. After the third filter clean – it pays for itself. You never have to buy a new filter.

My 6.5 liter turbo diesel Chevrolet K3500 was fitted with a K&N Air Filter by the previous owner. On the cold air box cover there is a K&N sticker with “STOP! Do not discard! This is a lifetime filter” clearly marked.

“What? I don’t replace my filter? Ever?” I thought.

After a little research I did find out that you need to clean this filter, and, yes, it requires a cleaning kit only supplied by K&N which costs about $15. The kit contains a spray on cleaner and then a special K&N oil to spray on after cleaning. The K&N filter oil is actually a special oil designed for the cotton filament. Once you have the cleaning kit, and a K&N filter, you never have to buy a new filter.

How is a K&N air filter any different from a normal air filter?

Normal air filters are made of fine tissue like paper which are designed to let air through and trap dust and contaminants from being ingested into your engine. Dust and dirt can scour cylinder walls and prematurely wear your engine.

Image of K&N cleaning and oiling kit

A K&N air filter is a natural cotton fabric enclosed in fine wire mesh. The wire mesh simply holds the cotton fabric in place, and the fabric traps the larger particles, while the special K&N oil adheres to the cotton filter forming a secondary filter that traps the finest of particles. K&N claims up to 99% efficiency which is verified by the ISO 5011 testing procedure.


Normal OEM paper air filters have an efficiency rating as low as 93% and it is a requirement to throw the filter away at the recommended period.

K&N filters are said to provide free flowing air to the induction of your engine at the same time as trapping more dust than a paper filter. Backing this claim is that a lot of high-performance racing engines do not even have a filter. While it’s impossible to have an engine last hundreds of thousands of miles, as with a normal road car or truck, without severe engine damage resulting from running.

K&N cold air intake for performance and classic cars

In my case, my 6.5 Detroit Diesel turbo classic Chevy truck thrives on clean free flowing intake air. A K&N Filter delivers this with optimum efficiency and I can clean my filter anytime. If you have a fuel injected gasoline engine with computer controlled efficiency, installing a K&N Filter may not be much of an advantage to performance, but you can still save on filter replacement costs, and have a freshly cleaned filter whenever you want.

K&N also supplies oil filters, inline fuel filters, and cold air intakes for all onroad, offroad, and commercial vehicles and motorcycles, ORVs and marine applications.

If you want to just have the hot appearance of an aftermarket filter, check out K&N today. I’m sure they will have just what you are looking for in looks, efficiency, and economy.


Newly added video demonstrates simple tests to prove the worth of K&N Filters …

Post Author: Alan O'Neill

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