[Dane!]

Now, I still have, and have only used, OEM Land rover Air filters.

Just as I asked previously with the installation of a MSD onto a D2, was just PURE CURIOSITY! Id like to make a discussion in the D2 forums instead of just constant horror stories.

I saw on Lucky8's website a green cotton air filter, I think Lucky8, a considerably respected rover parts supplier, would put something that would be bad for the truck (they didn't include K&N on there).

Looked it up and its supposed to provide better airflow and 20% more filtration than stock. I'm assuming they mean "stock" on a car or truck nowhere in the universe of a Discovery. I know K&N makes a filter for the Discovery, but when you install one, why even install a filter at all? I saw someone on this forum did an actual test comparing K&n vs Paper, K&N let tons of particles in, but I don't think Green Cotton was included. If I was to buy one, it wouldn't be to gain any MPG or hp, just for better filtration. I have heard the way its built is makes its sit really firm in the box so it wont let air/particles flow through the side, and its taller than stock, but the allowance of particles through the actual filter is what concerns me most.

Has anyone had a Green Cotton filter installed in the truck?
:beer:

 

[Disco Mike]

Do yourself a favor and only use a Rover brand filter other wise there is a good chance you will trash you MAF.

 

[Dane!]

I only do!!!!

As I said in the post, CURIOSITY!!!! haha.
I think a destroyed MAF is do to over oiling a K&N, I wouldn't want to personally test this though...

Again, has anyone used a green cotton filter?
Thanks.

 

[Bosnian Discovery]

I'm not sure how companies can promise "higher flow and better filtration" in a stock filter size. Those things are mutually exclusive. If the filter cross section stays the same then the only way you achieve better filtration is to either make the fabric element thicker or make the filter itself taller. Passing the same volume of air over a denser filter means the pressure drop will increase and the velocity of the incoming air will drop, leading to your engine working harder.

Once again, the driver will experience no measurable difference, but it's just comical to me that that can be their marketing standpoint. It defies physics.

You can get around this by installing a filter with a larger surface area or adding some sort of adhesive (filter oil) to more porous filters to help them trap more particles. That's the idea behind K&N.

As for the "K&N destroys MAF sensors" claim, I'm not sure if I believe it or not. K&N (obviously) states that it's done extensive testing and experienced zero MAF failures, but this theory seems to stick anyway. It makes sense. MAF sensors use microscopic heating elements that need to be perfectly clean to ensure accurate readings, but the oil in the K&N filters can (supposedly) migrate and foul them, leading to failures.

It's only partially true. K&N filters are inherently worse at filtering than OEM filters. They have to be to substantiate the "higher flow, more power" claim. The oil helps some with filtering, but it's in no way as good as a stock paper element. That means more particles pass across the filter and threaten the MAF. Furthermore, poor maintenance exacerbates the problem. People typically let their filters run WAY too long before cleaning them and as more particles are trapped by the oil, it becomes saturated and stops trapping, allowing even more dust to pass through. Then when they finally do clean it they do it improperly (don't let filter dry) and over-oil it, leading to noticeable oil migration and MAF damage.

K&N can say "it's not our fault people don't listen" and that's true, but people should know the facts.

Bottom line - you cannot improve on OEM paper filters.