I'm new to the board and I found your posts on k&n filters not working too well in discos with Bosch mafs. I have a 98 disco I and from what I have gathered, it does not have the Bosch maf like the newer disco 2's. My question is whether or not it is an issue with Disco I's? I installed a k&n filter about a month ago and I'm debating on whether or not to take it out. Thanks and sorry for bringing up a topic that has been discussed ad nauseum

 

It's when you over oil them you can run into issues. Most MAFs respond well to cleaning, well accept for DII MAFs. You are not going to get any extra performance out of them it is really just a cost saving thing because they are cleanable.

 

I had a D1 before i got my D2 and i always used paper filters just becuase i didnt want to have to bother cleaning the filter AND cleaning the MAF if oil got in it.

 

Just make sure that you do not over oil it. If you do there is a good chance that you will kill you MAF. The first thing that i do when i buy a new car/truck is ditch the paper filters and stick in a K&N in them. I have normally noticed a 1-2mpg difference, BUT with my disco i can't tell. JM2C

 

greenwade you shouldn't use a K&N in a D2. the MAF is really sensitive and you can't clean it and its expensive to replace.

 

If gaining 2 mpgs was as easy as putting in a high flow air filter all the auto makers would do it. 2 mpgs across the board would give their CAFE fleet numbers a definite boost. They don't so that should tell you something.

 

had a K&N filter in my 87 range rover and it improved performance. Had one in my 98 BMW 740 (with a Bosch MAF) and it messed up the MAF. I would and do stay with the paper filters in the DII.

 

They don't do it because they can't. The K&N style air filters are too expensive to produce and are not available in high enough quantity. The vast majority of the public is not smart enough to service them. They also supposedly reduce engine longevity.

Also, if there were no requirements for certain emissions components to be on vehicles, then automotive technology would probably be incredibly further along than it currently is. There is no competition, just mandates from bureaucrats who don't know how to design cars. Auto manufacturers can't make their cars more efficient, they are mandated to keep the design within certain parameters.

I put a K&N in every vehicle I own and clean it every 10k miles. I also try to bypass everything that kills efficiency and generally doesn't make sense and my cars last forever.

 

Yes auto manufacturers would do anything to add an easy extra couple mpgs across the entire fleet using something as simple as a high flow air filter. American auto makers would have saved tons of money in CAFE penalties. I mean they are going to 5w20 and 0w20 engine oils just to save a fraction of an mpg so that their averages go down. If a high flow air filter could instantly increase an vehicles efficiency by 5 to 10% in today's computerized fuel injected engines every car would have one and it would be disposable.

 

Why would you want an air filter that doesn't filter as well as the stock filter?
Engines like clean air.