How do you feel about K&N Filters?

Recently came upon this thread by hotrod53 about the long and exciting life if his K&N filter and I was surprised by the number of people who shared their reservations about running one in their Tacomas.

I had always taken it for granted that most people on here preferred running K&N to stock, but now I'm curious to hear more people's take on the matter.

How do you feel about K&N Filters?
Do you run one now, have you in the past?

 

I wouldn’t do it. The Toyota filters work fine and some people have definitely had problems with the K&N.

 

After taking apart my intake after owning one I will never install one again. It was caked with sand and grime.

They made sense in intakes from the 60s and 70s, with modern computer modeled intakes there is not nearly any loss from a paper filter.

 

Nothing but OEM/spec. Ran K&N for about 10k and that thing let so much crap in, all the way to and into the throttle body. I wised up and went back to OEM and my intake hasn’t needed a cleaning in 50k (my regular maintenance interval).

An air filter is not only blocking stuff you can see, but microparticles that you can't see. So if a K&N visibly let junk through, imagine the smaller ones that got by it and into the engine?

 

Jumping in on this because I went with the S&B kit for my Tundra years back, at first I liked it because of the oil kit I got as well, it came with a measuring fill bottle and the instructions on how much oil to use, plus I got an extra filter because when it was time to wash the used one, I had the other one ready and oiled, apparently you have to wait to let the filter "naturally" air dry, instructions say not to force air to dry it, I also checked the MAF sensor and throttle body at every oil change and found them to be a bit gunked up and I didn't like that, so I took the air filter kit off and sold it and out my stock air filter back on and stuck with oem filters, so if you get the kit or just the filter, be sure to check the MAF and throttle body

 

In 2000 I started running them on a Saturn S2 and an Xterra. We were in Houston so not a "dusty" environment. Too humid for that.

I found that cleaning them took forever to get them to dry and I was down a vehicle when that happened, so I needed to get 2 filters so one could dry and be oiled while the other was in the vehicle. Also, despite constantly backing down on the oiling, I was still having to clean the MAF Sensor. And it wasn't just oily, it had a lot of solid gunk on it.

The Saturn had a ridiculous warranty - like a life time or 100,000 mile bumper to bumper with a service package that lasted just as long. So I was taking it in to the Saturn Shop on the regular. Despite having all of the red and Orange K&N stickers on the Air Box and especially the big STOP sticker, Saturn routinely tossed my K&N and then dropped in a paper filter. Then I'd complain, then they would give me a new K&N out of the shop (they sold them right there). I think the third or fourth filter I forgot to check and didn't notice it until a week later and then I just decided to quit the K&N Shenanigan business. Amazingly my MAF Sensor Issues went away and each time I changed filters they were sparkling clean.

Specifically speaking the 2023 Tundra takes a smaller filter than the 2023 Tacoma does. If a smaller filter works for the Tundra (turbo charged and moving way more air) then the stock filter for the Taco is plenty. I think the only way you really improve upon the stock Tacoma design is to add in a Ram Air Scoop that has an efficient use of piping to eliminate as many bends as possible. And then, really, how much of an improvement you get is probably somewhere just north of nominal.

IMHO Toyota has consistently sold over 150,000 Tacomas every year since 1996. Just since the Pandemic that number jumps to 250,000. And that's US Domestic Sales. There are quite literally MILLIONS of these trucks on the road in the US alone. You can't throw a stone in a parking lot and not hit one. At that scale, if there was a meaningful improvement to be made. Gale Banks would have built an intake for it. Instead when you search for your truck on his site, you see that there are more shirts, hats, sunglasses, koozies, and coasters that "fit your truck" than there are actual parts for the Tacoma and most of his stuff is wiring and electrical monitors. No air filters. No air intakes. None of that stuff for us. So why pay extra for extra problems and maintenance that doesn't generate any extra performance?

 

Thanks for the in-depth response. I imagine you share similar views about other reusable filters, as well? I'm currently running a Magnum FLOW Pro 5R Air Filter, but all of these comments about MAF sensor gunk and what not have me considering returning to the OEM paper filters...

 

Total junk, but the sticker they include is nice, lets you know that the owner has been subjecting the engine to extra wear when you're looking to buy used.

 

I keep saying over and over if it ain’t broke don’t fix it. Been using regular old fashioned filters my whole life on dozens of vehicles. Never ever a problem. It definitely ain’t broke I aint going to fix it.

 

Pretty much. Nothing against K&N the brand but everything against the concept.
One of the things that used to be present in the K&N literature was how much better it worked when dirty because the dirt gets oiled and forms more filter material. Also people doing Used Oil Analysis over on BITOG were finding higher concentrations of silicon (sand) and wear metals in the oil.

Bingo!

 

I think they are not needed.
I have run one. (20+ years ago)

That's how I fell about them.

 

When I raced bikes, K&N were little more than gravel strainers. I wouldn't run one for sponser money!

FILTRON oiled Foam elements were the gold standard.

Pleated paper is the only thing I trust in my vehicles. Even then, rodents can undermine good intentions. Toss a couple moth balls in the air box when you have it open ;-)

 

Didn’t read anything else, but every engine I’ve ever seen in person that’s blown up, had an aftermarket intake or filter on it.


(besides extremely neglected stock engines)

 

If you read the fine print a K&N filter only improves performance when the engine is running 5000-6000 rpm's. And they do a poor job of filtering the air coming in. NOT a good choice for off-road use. If someone is building a dirt track race car a K&N might give them 1-2 mph better performance. And that might make a difference between 1st and 2nd place. I can see where it might be a good idea in that application.

I put one in a 1998 F150 that I had. Not really expecting any performance gains, but a paper filter for that truck was $16 at a time when most filters were $4-$5. A K&N cost me about $50. And since I never had to replace it (just clean it) I figured it was cheaper in the long run.

I never had any problems and never felt any gains in performance or fuel mileage. It was still in the truck when I sold it. I wouldn't do it again.

 

everything is a tradeoff.

higher flow means less filtering. higher filtering means lower flow. this is the same for every type of filter. oil, air, trans fluid, etc, etc.

i was into k&n style filters around high school. then i got a 'real' job, and with that, i had more money but less time. and with less time, means less fidgety stuff. like taking time to painstakingly clean and re-oil air filters for the cost of a new filter.

any aftermarket oil-type mesh filter, k&n, spectre in my case, or whatever the newfanglest Amazon overnight sensation brand is, are all the same. they sacrifice filtering capability for extra airflow. great for a race engine that only needs to last a few laps. horrible for an engine i need to get to work with for the next 10 years, and don't always have the money to replace with my socks like a race team.

 

My Pro came with the TRD filter …I take it out and replace it with paper if I know I’m going to be eating dust. Otherwise I like the TRD filter, truck seems to sound a lil better with it than with the paper filter. Haven’t noticed anything unusual with regard to dust and grime

 

I've seen them on a lot of vehicles and people really excited and saying they are great... and after a few years many of them take the filters off and say it's because of the expense and the cleaning that is necessary. And those that brag about their performance often wake up and say there was little or no difference.
Personally? I just see them as high priced glitter.

 

Had them in my 1992 Toyota Truck for 14 years and then my 2003 Pathfinder for 14 years. Re-oiled my Toyota truck’s K&N a few times. Bought a replacement after a few cleanings that were awkward or poorly executed. Pain in the ass in hindsight. Eventually went back to OEM near the end. Was the cool thing to have at the time.

Pathfinder, I never re-oiled it. Remembering my first experience. Meant to re-oil it but got busy with kids and other more important stuff. Neglected it the whole time and it seemed fine. They claimed it worked better the more dirty it got. I did eventually get a MAF sensor issue with the wicked away oil where the MAF needed to be cleaned.

OEM. Best bang for the buck.

 

I use their cabin air filters but not their engine air filters.

 

No issues running them in CA in a coastal climate. In AZ they dried out way too quick and let in too much sand. The cabin air filter was awful with my allergies. As previously mentioned I only use oem Toyota paper filters.

The 5.7 V8 uses the same paper engine filter, so there's plenty of flow.

I find the paper engine filters last about 7k-10k miles depending on dust storms and the cabin filters last anywhere from 3-5 months.