Air filter
 

Hi peeps,

Im looking to buy an air filter for my 2004 x5 3.0i just wondering if its worth it with the K&N one or should i just leave it stock?

Thanks any advice is appreciated.

If you're talking about the filter element, any sort of "gain" will be marginal. IMO keeping the factory air box and replacing the filter on a regular basis is a better option. I remember reading somewhere that the oiled filter elements such as those found in the aftermarket can cause problems with the MAF sensor over time.

Leave it stock not unless you have a wad of money burning a hole in your pocket.

Best filtering is with the OE filter. A paper drop-in aftermarket filter like a K&N is relatively low risk, but there are no upsides, unless it is a lot cheaper. If you are considering the oiled foam style, save your money, it is a waste. Lower filtering performance and a risk of MAF damage due to improper oiling. Those manufacturers spend all their product development money on advertising campaigns, which far too many people fall for.

While I use K&N drop in filters on my Miata's (they just replace the factory paper filter with an oiled cleanable element without changing any intake components) I went through the same decision making process on the X5 as you are thinking about and elected an OEM filter from Amazon (I forget if it was Mann or Mahle.) Just not worth potential aggravation and cost on such a complex and expensive to service vehicle.

Thanks guy ill leave it stock

UOA's with oiled filters show that they tend to make engines dirtier. switching to a CAI/SRI seems to be for show/sound only until you tune and go IHE

Mann filter.

hey, If you want a slightly used air filter K&N for the 3.0 than I could possibly sell it to you. I heard good things about the afe filter. Howeever, its not as cheap as a K&N.

I only have a K&N filter on my X because it came with the truck, otherwise I wouldn't have bothered with anything else other than OE. It's not really a performance bearing car with the 3.0i. I mean Dinan stage 3 for the 3.0i maybe nets you 15 hp at most? And thats exhaust, intake, software, throttle body etc.