i have one in my ride..im using it since 2years and till date i never had -ve effects from it..it gives your engine enough amount of air and it keeps your engine alive. my engine use to suffacate when i use to pull the RPM to an extent, but after i replaced my factory filter to K&N it can easily manage surviving those high RPMs. i suggest to have one
My service advisor said so and i've also come across many sites stating that.
The other option you have instead of a Stock replacement filter is a Cold Air Intake(CAI).Which requires a well calculated pipe is fixed with a conical filter.
As it is mounted on the engine and directly affected the air fuel mixture maybe it void warranty(This is what i think may be the reason)
my filter costed around 3100 + or - 200.
CAI gives your engine more air and that too cold air compared to stock filters and therefore more combustion takes place. this gives you more grunt and power, at the same time your engine wear and trear increases, and also some other parts get effected so that way it voids your warranty.
The air filter is a important part of you engine.In a stock set up there is a box in which lies the air filter.It has a sensor connected to it.
So in the stock replacement processes this filter in you box is changed to a K&N one.
Where as in Performance filters such as CAI,Conical filters,etc the complete stock set up including the filter box needs to be thrown out & a complete new set up with proper calculated pipe's etc is put up.It can harm you engine if not done properly.Hence you loose the warranty here.
stock replacement is the best way to go, there are other intakes as well where you need to change the whole setup of airfilters along with its conical box,pipe and its connnectors, which if not done properly would damper your engine a big way.Stock replacement with K&N, would just need to change filters and not the whole setup.
The filter can be given to the dealer,he cleans it up,oils it up & gives it back to you.You can do it on your own too but you need to buy the K&N cleaning kit.The processes is simple & given with the kit.
They provide you two stickers when you buy the air filter. First one which says (K&N) can be put up where ever you like.The second one which says (WARNING) do not discard the filter,etc is to be put on the Filter box so that the service center people don't throw it away thinking its a normal one.You can even mention "ABOUT NOT TOUCHING THE FILTER" while giving you car to servicing.They will write it on the Job Card of you vehicle.
The K&N filter has a different color(maroon),K&N markes here and there unlike your your stock filter(white). So you should be able to recognize if its been changed while servicing,etc