K&N Panel filters. Should you buy one for your car?
What effect do they have?
Let me start off by saying what K&N panel filters do NOT do. They do not give your car a noticeable increase in power (usually).
Power increases will usually be between 1-2% better compared to a NEW paper filter (old paper filter results will be different) so the power increase, if you get one, will not be noticeable.
So why would you fit a K&N panel filter if they do not increase the power of your car?
1.Throttle response. For whatever reason, fitting a freer flowing air filter improves the engine’s throttle response. I am not going to pretend why but the difference between pushing the accelerator and getting a reaction from the engine is less with the panel filter (in my experience)
2.Intake sound. You will hear more sound from the engine, specifically intake roar, which is probably a nicer sound that the exhaust, in most cases. The added benefit of intake sound is that you only hear it when you are accelerating. When you are cruising at a constant speed you do not hear anything. The same cannot be said for many performance exhausts!
3.Service life. To keep the original paper filter in top condition you need to change it regularly. A dirty paper filter will restrict air flow. A K&N panel filter is washable which means you simply wash the filter when it gets dirty and your filter is as good as new. A K&N filter cleaning kit has enough shampoo and filter oil to clean a panel filter many times. In short a K&N panel filter should save you money in the long run and also create less waste as you are not throwing away air filters.
So is a K&N filter worth it? Is a K&N air filter any good?
It depends what you want/need from your air filter, if the benefits are what you want then probably. If you were looking for big power gains you are probably looking at the wrong type of product, it is rare for any type of air filter to give noticeable power gains but the improved throttle response can give the impression that the engine is making more power.