No K&N Controversy here?

[Kuhnman]

I've found over the years that the K&N can in some cases be better but with the vehicles I've seen with them in have failed due to miss use (too much or not enough oil, cleaning too often and using compressed air to dry them) For the most part, miss use seems to be the killer. I've used them and found no difference in power and gas milage. The worst application that I've seen by far is a diesel truck, Cummins, Powerstoke, and Duramax applications. The fitment always seems poor causing the engine to get dusted which is easy with the high combustion nature of a diesel. Not to mention the rather large air volume. Most diesel engines with K&Ns I've seen have a bad film of dust on the clean side of the intake tubes and I've replaced engines due to this. I think they're fine in a car as long as they are maintained properly and keep an eye on the fitment and the intake tubes for any signs of dust getting in. I'm just going by my years of experience as a mechanic and what I've seen, not by tests because it seems that there is always a test that proves another test wrong which leaves you wondering who really knows for sure! For the average joe with minimal experience, I think sticking to a good quality paper filter is the best way to go.

[wiltshireman]

On my 2000 v70 2.4 I have recently replaced stock air filter with k and n item. I am not a professional and I have no way of measuring output but first thing I noticed was tickover speed more even and slightly lower. On test drive its much smoother at low speed and I didnt have to push so far down on the accelerator to get what I was after. When I got onto open road and put my foot down the difference was amazing, much quicker and quieter and smoother.

I have also noticed about 3/4 mpg impovement on fuel consumption according to the cars computer. I am resisting the temptation to drive hard at the moment.

I plan on keeping this car for a few years so I thought the extra cost was worth it (and I still do). standard filter costs 10 british pounds - kn costs 30, so it will pay for itself soon enough, especially with improved fuel economy.

No other modifications carried out - just replaced as part of service, which has been done regularly up to now.

Just wish I had put one in my old 940 and 240 as well. It sure gets a thumbs up from me.

[gilhuly]

I have 191k on my MAF (stock), 90k miles on the K&N. Turbos need to flow air. K&N inhibits air flow less while keeping out danmaging grit and big stuff. BTW, I think you can oil these with any thick oil and you definitely can clean them with simple green. Again, light on the oil.

[tjts1]

K&N inhibits air flow less while keeping out danmaging grit and big stuff.

Not true.

[davis911s]

If you replace your air filter box with a cone filter, I will simply be forced to laugh at you.

Sorry for being niave, but what is bad about the cone filter? I have thought about getting one for my car, don't want to throw money away but I have heard of good results from cone filters in other cars. Sorry for going a bit off topic.

I have a turbo if that matters at all

[C@lvin]

Long term update on MPG before and after installing the K&N on my 98 S70 (NA/4 Speed Automatic) 202K.....

I have now put about 14K Miles on it in 11 months since the K&N filter was installed. Here are the MPG calculations from both before and after. These are manual calculations. The car doesn't have a trip computer.

04/09 to 12/09 3941 Miles 22.29 MPG
12/09 Installed K&N
12/09 to 03/10 4138 Miles 21.18 MPG
04/10 to 07/10 3521 Miles 20.99 MPG
07/10 Seafoam Treatment (gas tank, crankcase and intake)
07/10 to 11/10 5186 Miles 22.24 MPG

Nearly all of these miles were logged in my daily commute of about 54 miles round trip. The first, second, and fourth mileages included a little extra highway driving during my work day. The last MPG calculation also includes an approximately 240 mile round trip drive on the Interstate (55MPH - 80PH) during which I got 26.1 MPG.

Prior to any of this, I had already installed a 960 throttle plate and disabled the airbox thermostat in the ambient air mode.

I don't consider the MPG variances to be "statistically significant". You can draw your own conclusions. As for me, to date I am happy with the K&N.

There have been no instances of DTC errors in this time, but Interestingly enough (if you've read the discussion above regarding K&N and MAF sensors) I did recently have repeated MAF error codes on my 00 V70 (NA/5 Speed Automatic) 120K that is using a paper filter. I cleaned the MAF using CRC MAF Cleaner and the codes ceased.

In case it's of interest, the V70 (paper filter, electronic throttle, 5 Speed Auto, and more conservative driver) has averaged 22.4 MPG over the previous 9K miles according to its trip computer.

[brady55]

the k&n filters are worth their money if for no other reason than you never have to buy a filter again so yes you spend 50 dollars up front but after about 50k it has paid for its self in replacements you did not have to buy. and with the miles that volvos (and other cars) can handle its very easy to save money with the k&n regardless of performance or MPG improvements

[Dad03]

My local Pull a part yard put a fresh 850 on the lot. I got to it rather quickly. It had a good K&N in the air box. So i got it for a buck. Took it home clean it with their kit I had from other vehicle.

My 850 turbo has definite improved throttle response!

[tjts1]

MANN filter is still cheaper, filters better and flows more air.

[Red-Arrow]

Honestly tell the Saab 9-5 guys that they should clean the AMM or MAS more often and not to put to much oil on the K&N filter.

In all honestly I have found no benefit to the whole after market performance filters. The only way to decrease drag is to have a very large area filter body to lower the air drag. If a filter is allowing more airflow its allowing more particulates in as well. Filtration is not magic, its simple process. Its very easy to sell the Fast and Furious mob with a fancy name and logo.