What's the deal with K&N filters? Are they worth it?

[wrestrepo]

Aside from all the walls full of them at the autopart store, I know nothing about them. I need to replace the air filter for my Acura; I was wondering if their are really worth the extra money. They say that you won't have to replace them, but you need to clean them, and there are products they sell you for that too....so, is it worth to purchase the more expensive filter, and also buy the cleaning supplies, than just buy the conventional replacement filter? Thanks in advance for the feedback.

This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Acurazine!

[mav238]

Originally Posted by wrestrepo

Aside from all the walls full of them at the autopart store, I know nothing about them.

I need to replace the air filter for my Acura; I was wondering if their are really worth the extra money. They say that you won't have to replace them, but you need to clean them, and there are products they sell you for that too....so, is it worth to purchase the more expensive filter, and also buy the cleaning supplies, than just buy the conventional replacement filter?

Thanks in advance for the feedback.

Many folks use them to hopefully gain some performance and fuel economy benefits. In principle, more air equals more power (because the engine ECU will dial in more fuel to maintain air/fuel ratio).The turbo engine should benefit from this...

From my experience with these drop in factory replacement high flowing air filters, the gain in power is not really detectable, at most 5-10% and this is at the top end of the power band. But that is still pushing it... I have used them before in my SAAB 9-3 2.0t turbo, and never really detect any real fuel economy gains.

Another thing, KN filters have less of this issue, but it can happen, sometimes, due to the factory not priming the filter properly with the oil, too much oil can end up having the MAF sensor coated with a fine mist of the oil. ITG high flow filters had this problem... KN should be better in this quality respect, but a defect in factory manufacturing can occur.

Now $50 for 50,000 miles. Honestly, I don't think one will wait the 50,000 miles to clean the filter. Typically, it will get cluttered with all sorts of dirt, given the oil tendency to trap these things. So you will probably end up cleaning it once or twice a year. And unless you are a handy DIY person, you have to know how much to re-prime the filter with oil... too much issue for MAF, too little, not properly trapping all the dirt flying through...

IMHO, the minimal gain in performance and fuel economy, is not worth the hassle of owning one... I mean, if we can see 20-30% gain in performance and fuel economy, I would definitely recommend it.

KN drop-in filters are good quality filters in general... but not sure if it really is superior over the factory filters.

You want real performance gain, get a real high-flowing intake that rams in cold dense charge of air, CAI; and throw in a highly efficient water mist sprayed intercooler...

[bgillette79]

I love the drop in ones. I have first hand experience with them.

Have used them for 7-8 years now and every single car I have had them in it has made a difference. IN the RDX in particular I have noticed the the response of the car is better. And I've noticed about an extra 1-1.5mpg city and 2-2.5mpg extra HW just by adding this filter.

I clean mine about once a year (so about 12000-15000miles).

For under $50 you cannot beat it...it pays for itself with the 1-2extra MPG it gives you and the filter costs over time.

[MMike1981]

well...the top end power is where it counts, because the RDX runs out of breath when the turbo coughs out, and, there is better initial throttle response, plus better mileage. so, id say the benefits outweigh the fact that you have to clean it every 15k. in terms of what mav is talking about, sounds like he hasnt used one in the RDX because hes talking about his 2003 saab.

Every car may behave differently, changes are not automatic. It seems as tho the RDX likes the K&N, and all numbers & feel point to that in my experience since using from last spring.

I can tell you that i noticed immediate benefits, i saw an overall 1-2mpg increase in city, and more in highway miles- the benefit is CONSISTENT mpg increases.

The air flow is increased, you can hear more air rushing in, and the whine is more powerful.

k&n claims clean every 50k...if you put one in, itd be wise to visually check it around 15k....the thing can get crazy dirty and you just dont know the situation under there without looking at it. i pulled one at 20k and it was more than 3/4 caked.

not sure what mav is talking about "hassle of owning one" 50 bucks and a cleaning kit ur good for a very long time, its basically hassle free, not an actual hassle. Its a minimum cost upgrade vs 300 for a cai, and you are also materially altering the engine and may run into problems with your dealer. so in that regard, what is not worth it is the CAI

[SinCity]

I have used K&Ns since the 80s without incident. I currently have them in my '08 RDX and '09 C63 AMG.

[corduroygt]

I have the K&N filter and aside from slight intake woosh, I haven't noticed anything. My mileage didn't seem to improve. I don't think it really improves mileage, because if you look at it, I'm sure Honda would kill to get 1-2 mpg extra just by adding a filter that retails for $50 they could probably get for $20 or less when buying in bulk. They went through all the trouble to develop a fwd version, I'm sure changing the air filter for cheap and advertising 1-2+ mpg would be an extremely good deal.

[MMike1981]

its all about cost. your argument could be posed about any facet of any car; the reason why a better filter is NOT in the car is cost, that does NOT mean that a better filter doesnt exist. I wonder why many car companies offer aftermarket filters (pretty sure corvette can be ordered w/K&N, etc) as an OPTION...they are not going to give you an upgrade for free...to spread the cost out across the entire line is not worth it with something as EASY as going to a store, buying it, and popping it in. even tho it may be of minimal expense.

just because honda didnt add a "better" filter has nothing to do with such a filter giving better mpg.

the results are usually in K&N's favor or other like filters (i like green filters, but they do not make one for the RDX) one of the first things to go in a high performance car is the way it breathes, short of a CAI, this is the first step for performance minded people

[mav238]

Originally Posted by corduroygt

I have the K&N filter and aside from slight intake woosh, I haven't noticed anything. My mileage didn't seem to improve. I don't think it really improves mileage, because if you look at it, I'm sure Honda would kill to get 1-2 mpg extra just by adding a filter that retails for $50 they could probably get for $20 or less when buying in bulk. They went through all the trouble to develop a fwd version, I'm sure changing the air filter for cheap and advertising 1-2+ mpg would be an extremely good deal.

I totally agree. But to each his own, some folks here get a real kick out of the increased suction sound "whoosh", giving the placebo effect that the car feels more powerful and responsive.

My RDX as it is now, with a brand new Honda air filter in it, feels as peppy as the first day.

And you are right, Honda will do all it can to advertise that it gained 1-2 mpg by using a KN filter in the car. And probably get KN to manufacture that specific part for them and have Honda exclusively sell it.

If you really want real improvement in performance and fuel efficiency, revamp your whole intake (with a CAI) and also put in a super efficient extractor/exhaust system, plus the ECU upgrade to handle the improved intake and exhaust.

[wrestrepo]

I thank all the people that provided feedback. I also posted this question at a Saab forum (my other car) and the opinions were very similar. KN drop ins don't offer any significant improvement to performance or economy. They do however provide an added risk to causing damage to your car if the filter is not maintained properly. In terms of money, what you save in replacements is quickly spent in the cleaning supplies (there is no free lunch), so long term savings don't occur.
I respect all the people that do like the KNs, and that feel and have measured improvements.
Based on the overwhelming amount of "not worth it" opinions I ordered my paper replacements yesterday from autoanything.com (I think MAV used them) because of the free shipping, no store around me carries the filter and they want me to pre-pay and come back to pick it up, and they don't allow me to pay over the phone...F that....

Thank y'all

[MMike1981]

well..i guess others dont see results. but my mileage has gone up since the day it went in. I swapped it out for a few months last year, and mileage went back down. so besides the mileage, which of course is not a placebo effect, i noticed off the line responsiveness, and throttle tip in responsiveness that MY RDX never had before...

to each their own is right.....but there are hard numbers that back them up

[wrestrepo]

Originally Posted by MMike1981

well..i guess others dont see results. but my mileage has gone up since the day it went in. I swapped it out for a few months last year, and mileage went back down. so besides the mileage, which of course is not a placebo effect, i noticed off the line responsiveness, and throttle tip in responsiveness that MY RDX never had before...

to each their own is right.....but there are hard numbers that back them up

As a matter of fact, the results of installing a KN are split between positive and none. Some people MEASURED more mpgs, and NOTICED "increased performance", some people didn't. However, the majority of people had concerns about causing damage to the MAF if the filters were not properly maintained, something you don't have to worry about with paper.

[BigHatch]

it's pretty "fool"proof... you'd have to be one to install the thing dripping wet.

common sense keeps you safe. I've never had issues with my K&N's over the years.

[wrestrepo]

This is at 30K....wow, they were pretty dirty....

On a side note, Autoanything.com seems to be great...the filter I got was a Honda filter, which I think it's the OEM for 20some dollars, ordered yesterday afternoon and arrived to my door at 4pm.

For those who are starting to do DIY, I found that removing the engine cover facilitated access to the engine filter.

[MMike1981]

Originally Posted by BigHatch

it's pretty "fool"proof... you'd have to be one to install the thing dripping wet.

common sense keeps you safe. I've never had issues with my K&N's over the years.

yea exactly

also...there is a difference between "noticing" and measuring. I dont "track" my mpg...but since i put it in my city miles have not dropped below 17. My commute doesnt change, at all. i do the same thing, every day, same places (pretty horrible) throw in the weekends maybe some variety. My rdx mileage was routinely 15 city, 18 highway. K&N its 17 city and 20+ highway.

as far as noticing performance...ive swapped in and out the stock vs k&n...although i have no way of measuring performance characteristics, i know my truck is behaving differently when i put the pedal down. Beyond that, take it for what its worth. I ahve left the stock in for a few weeks, and K*N for a chunk of time and repeat (i did this last year) and when doing so the throttle mechanics were better, and pick up was better...yea you could say there is a split in ppl who see benefits vs people who dont...but imo, the trucks drivability is better with the K&N.

[mav238]

Originally Posted by MMike1981

yea exactly

also...there is a difference between "noticing" and measuring. I dont "track" my mpg...but since i put it in my city miles have not dropped below 17. My commute doesnt change, at all. i do the same thing, every day, same places (pretty horrible) throw in the weekends maybe some variety. My rdx mileage was routinely 15 city, 18 highway. K&N its 17 city and 20+ highway.

as far as noticing performance...ive swapped in and out the stock vs k&n...although i have no way of measuring performance characteristics, i know my truck is behaving differently when i put the pedal down. Beyond that, take it for what its worth. I ahve left the stock in for a few weeks, and K*N for a chunk of time and repeat (i did this last year) and when doing so the throttle mechanics were better, and pick up was better...yea you could say there is a split in ppl who see benefits vs people who dont...but imo, the trucks drivability is better with the K&N.

Interesting... I have been getting 17-18 mpg city and 20-21 mpg freeway, from day 1 up to now currently, and it has been with simply my HONDA oem filters. I think I can even better that, if I drive with less of a lead foot on the gas pedal.

I don't deny there is a somewhat "detectable" difference in the way the engine respond, a bit more whoosh, more responsiveness (?)... but is it a "night and day" difference, or are we talking about 1-2 HP gain?

240HP vs 243hP... a significant gain? for $50?

[corduroygt]

I have to add although I didn't notice a fuel economy improvement, I was expecting as much, and I still prefer the car with the K&N to without it. The intake resistance is less, and I notice that the RDX doesn't seem to get caught flat-footed at low speeds as much as it did with the stock filter. There used to be a good 1.5 second delay when I was coasting to a stop and had to get back on the gas at 15 mph, now it's about half that.

I feel like it did improve turbo spool-up speed, which is good in my book. Besides I still have the stock filter and can use it till it's all clogged up, although I don't want to, I do like the performance of the RDX better with the K&N.

About costs, Acura went through the effort of removing AWD and redoing the transmission to get better mpg from the RDX. If there was a magical way to get 2mpg with just a cheap air filter, you can bet ALL auto manufacturers would be doing it.

[mav238]

Originally Posted by corduroygt

I have to add although I didn't notice a fuel economy improvement, I was expecting as much, and I still prefer the car with the K&N to without it. The intake resistance is less, and I notice that the RDX doesn't seem to get caught flat-footed at low speeds as much as it did with the stock filter. There used to be a good 1.5 second delay when I was coasting to a stop and had to get back on the gas at 15 mph, now it's about half that.

I feel like it did improve turbo spool-up speed, which is good in my book. Besides I still have the stock filter and can use it till it's all clogged up, although I don't want to, I do like the performance of the RDX better with the K&N.

About costs, Acura went through the effort of removing AWD and redoing the transmission to get better mpg from the RDX. If there was a magical way to get 2mpg with just a cheap air filter, you can bet ALL auto manufacturers would be doing it.

I totally agree with your last point. Any slight gain in fuel economy with the KN filter (~ 1mpg), you can probably achieve that by driving a bit less aggressively.

When I had my 2003 SAAB 9-3 2.0t turbo, I was looking to an aftermarket full cold air intake system + new intercooler + ECU upgrade + high-flow low restriction exhaust. When it claimed a whopping 80 HP + 60 lb/ft increase in performance, I actually believed it. The company actually will dyno your car for you and confirm the increase in performance. The upgrades the company provided were specific to the car model. Thus they actually had a system matched to my SAAB. But the cost of ~ $1500 was a bit prohibitive. If money was not an issue, for that kind of performance increase, it would have been worth it.

Honestly, 1-5 HP gain is miniscule enough not to mean much in everyday driving. It might give you the "it feels peppier" or "more responsive" feeling, but no real detectable push in the back increase in performance. But if a high flow drop-in filter gave a true 1-5HP gain in performance, Honda will be all over it, and specified it as factory part, and charged the same amount of money for a similar type of filter (probably made by FRAM and labeled Honda).

[MMike1981]

Originally Posted by mav238

Interesting... I have been getting 17-18 mpg city and 20-21 mpg freeway, from day 1 up to now currently, and it has been with simply my HONDA oem filters. I think I can even better that, if I drive with less of a lead foot on the gas pedal.

I don't deny there is a somewhat "detectable" difference in the way the engine respond, a bit more whoosh, more responsiveness (?)... but is it a "night and day" difference, or are we talking about 1-2 HP gain?

240HP vs 243hP... a significant gain? for $50?

im not going to talk about real HP numbers, because, who the hell knows unless you are dynod..but like cord admitted..there is noticeable difference in throttle response, which i have been saying all along. whether that equates to more HP being made, or just better intake & spooling, i dont know, nor do i care, i just know what i feel, and the car drives better with it in, vs out. my mpg was terrible with the stock, and the K&N provided relief across teh board.

thats the long and short of it.

they made an AWD model to move more RDX's by lowering the buy in, yea you can say they are motivated by MPG...but that is not the pure motivation, come on. a company doesnt rip out AWD because it just wants to improve mileage lol, it makes the car more affordable, lowers the sticker 2k (thats roughly -40/month to buyers) and people who DONT want AWD now have an option, based on where they live etc. Makes the care appeal to a bigger audience, yea mpg helps, but this was to SELL RDX's for a multitude of reasons.

Cord, not sure where you found a "redo of the transmission"...the better mpg is pure weight and dropping of 2 wheels.

the 2010 MDX got mpg relief by some rework and a 6th gear, which only equated to about 1, maybe 2 mpg.

[corduroygt]

I thought they changed the gear ratios of the fwd rdx. I love just mashing the gas in the middle of a turn and have the back end push me through the curve. They don't call the Rdx the evo of crossovers for no reason. So awd for me an I'll pay at the pump. Also k&n makes the car more fun to drive although it doesn't effect measurable performance or fuel economy so it's worth the money for people who enjoy driving and exploring the performance of their cars.

[mav238]

Originally Posted by corduroygt

Also k&n makes the car more fun to drive although it doesn't effect measurable performance or fuel economy so it's worth the money for people who enjoy driving and exploring the performance of their cars.

I guess I am not sure what measurable performance is like... Probably is: You can "feel" the difference, but not a really measurable or significant increase like 20-30HP. I guess, for some folks, this would work well for $50 investment.
I have done this before, in my SAAB 9-3 2.0t, and also "felt" the difference, but after a while, realized that, it is not really a significant difference to the factory airfilter. Basically, not a night and day difference...

but again, it works and satisfies some folks...

Now, I am personally more in line with, if really need to feel the improvement in performance, go for the real thing, CAI, ECU reflash and high performance exhaust to boot. It won't be the "I can feel the difference" anymore, but a real kick in performance... Especially if I have spend time TLC'ing the filter, I want some real performance out of that...

JMHO

[MMike1981]

dude...ur comparing apples and oranges. You cannot say, dont get the K&N, get an ECU etc. thats a totally different ballgame. for 50 bucks the K&N is the best thing for this car. 50 bucks is way more justifiable than 300 and an alteration to the engine for a CAI. Most people are not going to go that far for improving the driving mechanics.

no one is looking for a night and day difference or assuming the solution IS an air filter. If you are in the game for a night/day difference, you are not starting with the air filter at all, although an upgrade or CAI is of course in your plan. of course an air filter is not going to give you performance equal to or better than a REAL PERFORMANCE UPGRADE. i dunno why you keep trying to make those comparisons.

kicking a dead dog.

[TL Dream]

I got the K&N to avoid throwing used filters into the landfill as well as the CO2 from shipping new filters to me.

[wrestrepo]

Originally Posted by TL Dream

I got the K&N to avoid throwing used filters into the landfill as well as the CO2 from shipping new filters to me.

do you drive a Prius?

[mav238]

Originally Posted by MMike1981

dude...ur comparing apples and oranges. You cannot say, dont get the K&N, get an ECU etc. thats a totally different ballgame. for 50 bucks the K&N is the best thing for this car. 50 bucks is way more justifiable than 300 and an alteration to the engine for a CAI. Most people are not going to go that far for improving the driving mechanics.

no one is looking for a night and day difference or assuming the solution IS an air filter. If you are in the game for a night/day difference, you are not starting with the air filter at all, although an upgrade or CAI is of course in your plan. of course an air filter is not going to give you performance equal to or better than a REAL PERFORMANCE UPGRADE. i dunno why you keep trying to make those comparisons.

kicking a dead dog.

I guess I don't understand why one would spend $50 just to get that "I can sense a difference in performance" feeling... no realistic HP or torque gains, or even realistic fuel economy benefits... When you say better for your car and best thing that one can do for our car for $50... that would be pushing it... feeding more air into the car does not automatically mean performance gain... it depends on whether the extra air is a cooler denser charge, or simply more "hot" air... that is why CAI makes more sense...
Its like in drug clinical trials where they test the real drug against a placebo... the "placebo" effect can sometimes effect a "detectable" difference... the latter has been documented many times...

[CSpaR]

Originally Posted by mav238

I guess I don't understand why one would spend $50 just to get that "I can sense a difference in performance" feeling... no realistic HP or torque gains, or even realistic fuel economy benefits... When you say better for your car and best thing that one can do for our car for $50... that would be pushing it... feeding more air into the car does not automatically mean performance gain... it depends on whether the extra air is a cooler denser charge, or simply more "hot" air... that is why CAI makes more sense...
Its like in drug clinical trials where they test the real drug against a placebo... the "placebo" effect can sometimes effect a "detectable" difference... the latter has been documented many times...

I have a K&N and do notice a difference in the milage. I can see a 2 or more gain in mpg. To me, yes it is worth $50. Is cleaning it once a year a big deal? No ofcourse not.

I think there are enough of us who have used them and agree there is a noticable increase in mpg to say it's a good product for the money. If you dont agree, then dont buy one and move on instead of saying we who believe there's an increase are like those who take sugar pills.

[TL Dream]

Originally Posted by wrestrepo

do you drive a Prius?

No, I'm just yanking the chain...

My RDX got 1mpg more with the K&N, so I should have it paid off in 5 years or so.

The performace is not noticable. I could hardly tell a change with a 4inch tall K&N on my 380HP small block 57 chevy, so I didin't expect much change on the RDX. Only at the higher RPM range would there be a change and there is enough power there already!

[MMike1981]

all set with this thread.

[corduroygt]

It makes the turbo lag less pronounced, and that's worth $50 to me.
I think because of the less turbo lag, you don't end up mashing the throttle as much with the K&N, thus the improved mileage for some. All car manufacturers spend billions to improve mpg, and if it was easy as a $50 retail filter, they'd all be doing it, since they can get that same filter for less than 10 bucks. So while it objectively doesn't change much, it makes the car feel more responsive, which in turn changes driving habits and improves mpg, this is my theory.