[Boz]

I recently fitted a new standard air filter to my 2012 TDi Eos, but while looking for a replacement air filter I saw an ad for a washable K&N Air filter , which claimed good performance and mpg etc etc, is this something to be avoided or recommended ?
Thanks
Boz

 

[voxmagna]

I only had one bad experience of a K&N filter fitted to EFi Superbike and I will never use them again: The filter I used was their washable and re-oil type. The oil they supply is very viscous (sticky) similar to a chainsaw chain lube. I fitted it pre-oiled straight out of the box (it came with spare oil). After using it for 6 months (with increased induction noise) I had to tear down the upper engine which included 4 precision throttle butterfly stubs located downstream of the air filter.

And then to my horror, I saw the nice precision made throttle bodies and jets covered in brown sticky oil with particles stuck to it, brought down from the K&N filter by induction. It created a real mess to clean up and the presence of small particles told me it was letting a lot of air and everything else through.

Air filters of the folded large area paper type are still the best at giving clean high volume air to your engine. Aftermarkets from well known firms like Bosch etc are very good and not expensive. But if you want to get taken in by K&N promotion, try one and I hope you don't have the same bad experience.

If you want better mpg, consider a Stage 1 ECU reflash. You may get 58-62 mpg cruising with a Tdi. No K&N filter will give that kind of mpg improvement.

 

[bozhound]

I only had one bad experience of a K&N filter fitted to EFi Superbike and I will never use them again: The filter I used was their washable and re-oil type. The oil they supply is very viscous (sticky) similar to a chainsaw chain lube. I fitted it pre-oiled straight out of the box (it came with spare oil). After using it for 6 months (with increased induction noise) I had to tear down the upper engine which included 4 precision throttle butterfly stubs located downstream of the air filter.

And then to my horror, I saw the nice precision made throttle bodies and jets covered in brown sticky oil with particles stuck to it, brought down from the K&N filter by induction. It created a real mess to clean up and the presence of small particles told me it was letting a lot of air and everything else through.

Air filters of the folded large area paper type are still the best at giving clean high volume air to your engine. Aftermarkets from well known firms like Bosch etc are very good and not expensive. But if you want to get taken in by K&N promotion, try one and I hope you don't have the same bad experience.

If you want better mpg, consider a Stage 1 ECU reflash. You may get 58-62 mpg cruising with a Tdi. No K&N filter will give that kind of mpg improvement.

Ok, thanks for the reply, I think I'll stick to the standard paper filters, I don't want to risk any damage etc, I'm not very mechanically minded and just wanted an opinion on these filters .
Thanks
Boz

 

[voxmagna]

Lots of people buy them but few probably tear into their engine and see what I saw. I usually shop around for Bosch or Man brand filters and buy a few at a lower price. Same with oil and other filters.

 

[2phast]

I recently fitted a new standard air filter to my 2012 TDi Eos, but while looking for a replacement air filter I saw an ad for a washable K&N Air filter , which claimed good performance and mpg etc etc, is this something to be avoided or recommended ?
Thanks
Boz

I have used K&N filters in all my cars for well over 20 years. Never have I had any issues with oil getting onto the MAF. During every oil change I check my filter and check the MAF.

IF you oil the wrong side of the filter or use too much oil, its possible you can run into this problem, but again, the number of people who experience this are very few compared to the number of filters on the market.

In my 500E, I had a set of K&N's in it for 15 years.

Now, don't expect large gains from a K&N, on some cars you might see 5-7 hp on other cars you might not see any performance gain. Much depends upon the stock air intake system and the stock filter. On different cars I have used these filters on, I have see from 0 hp gain up to 17 hp gain, with the latter being on a 2000 Corvette.

I have a K&N in my VR6 EOS, but along with the installation of the filter, I have removed the flapper valve inside the airbox. This valve ate up 1/3 of the total airbox volume and also draws in hot air from the engine bay. Also, the snorkel at the front of the airbox was also designed not only to draw air from the grill but to draw air from the engine bay. This engine bay opening was also sealed up. Lastly, the accordion tube that connects the MAF to the TB, is small in diameter and under hard acceleration, collapses in on itself. So to allow more airflow and a eliminate air turbulence into the TB, the accordion tube has been replaced with a larger, hard silicone tube made by ECS

Performance from a air intake is also enhanced by ECU tuning and a performance exhaust.

 

[2phast]

I recently fitted a new standard air filter to my 2012 TDi Eos, but while looking for a replacement air filter I saw an ad for a washable K&N Air filter , which claimed good performance and mpg etc etc, is this something to be avoided or recommended ?
Thanks
Boz

Forgot to mention.

If you are absolutely set against a performance filter that has to be oiled. There are "dry" performance filters on the market. Piper Cross and AFe both have them. Due to them not having oil, the material needs to be thicker and thus, don't expect the same gains as an oiled filter. But in most all of the tests I have seen, a vehicle that gains say 7 hp with a K&N, may only see 3-4 with a "dry" performance air filter. Still better than stock.

FWIW, K&N has the highest airflow rate than any other filter, dry or oiled.

https://www.ecstuning.com/b-afe-parts/pro-dry-s-drop-in-filter/31-10172~afe/

https://www.ecstuning.com/b-pipercross-parts/performance-foam-air-filter/pp1624~ppc/

 

[bozhound]

Forgot to mention.

If you are absolutely set against a performance filter that has to be oiled. There are "dry" performance filters on the market. Piper Cross and AFe both have them. Due to them not having oil, the material needs to be thicker and thus, don't expect the same gains as an oiled filter. But in most all of the tests I have seen, a vehicle that gains say 7 hp with a K&N, may only see 3-4 with a "dry" performance air filter. Still better than stock.

FWIW, K&N has the highest airflow rate than any other filter, dry or oiled.

https://www.ecstuning.com/b-afe-parts/pro-dry-s-drop-in-filter/31-10172~afe/

https://www.ecstuning.com/b-pipercross-parts/performance-foam-air-filter/pp1624~ppc/

Ok, thanks for all the info which is always helpful.

 

[2phast]

I only had one bad experience of a K&N filter fitted to EFi Superbike and I will never use them again: The filter I used was their washable and re-oil type. The oil they supply is very viscous (sticky) similar to a chainsaw chain lube. I fitted it pre-oiled straight out of the box (it came with spare oil). After using it for 6 months (with increased induction noise) I had to tear down the upper engine which included 4 precision throttle butterfly stubs located downstream of the air filter.

And then to my horror, I saw the nice precision made throttle bodies and jets covered in brown sticky oil with particles stuck to it, brought down from the K&N filter by induction. It created a real mess to clean up and the presence of small particles told me it was letting a lot of air and everything else through.

Air filters of the folded large area paper type are still the best at giving clean high volume air to your engine. Aftermarkets from well known firms like Bosch etc are very good and not expensive. But if you want to get taken in by K&N promotion, try one and I hope you don't have the same bad experience.

If you want better mpg, consider a Stage 1 ECU reflash. You may get 58-62 mpg cruising with a Tdi. No K&N filter will give that kind of mpg improvement.

K&N oil is red, not brown BTW. Even when dirty, its still obvious its red

 

[voxmagna]

I bought mine about 10 years ago and it came out of the box pre-oiled with sticky brown oil which the instructions said were its first oiling. I haven't bought one since and wouldn't know what oil they use or what color it is.

 

[2phast]

I bought mine about 10 years ago and it came out of the box pre-oiled with sticky brown oil which the instructions said were its first oiling. I haven't bought one since and wouldn't know what oil they use or what color it is.

Hmm, given I have been using them for 20 plus years, have never seen anything but red oil on the filter or in their refill bottles. Maybe its different for motorcycles, something I have no experience with.

 

[voxmagna]

Maybe its different for motorcycles,

More & faster induction rate (acceleration?) and smaller parts (4 separate throttle intake stubs) in a compact light weight 150bhp engine?