Does anyone here have any experience with K&N air filters? I'm thinking about getting one to improve current gas mileage. Their website states that one may or may not experience increased fuel economy.

5/1/2011 7:32:36 PM

increased fuel economy at a cost of increased cylinder and ring wear. change your paper filter regularly and all will be right

5/1/2011 8:00:28 PM

it increases fuel economy because it don't filter worth a fuck

plenty of information all over the internet on why they suck

[Edited on May 1, 2011 at 8:06 PM. Reason : for everyday street applications]

5/1/2011 8:05:59 PM

If its for a gm, don't get it. The grease gets on the MAF senesor and fucks it up.

5/1/2011 9:45:24 PM

+100whp

it's a 'performance' air filter

dont over oil it


I'd recommend AFE or S&B filter

5/2/2011 8:25:54 AM

how exactly does increasing airflow increase fuel economy? wouldn't it reduce economy?

5/2/2011 9:23:42 AM

less DP across a K&N filter

just like a dirty filter will hurt gas mileage and a new clean one will improve mpg

[Edited on May 2, 2011 at 10:24 AM. Reason : engine doesn't have to suck as hard to pull air through the filter]

5/2/2011 10:23:20 AM

^^ Well if you don't tune it then you're running leaner. less gasoline consumption so better mpg I guess at the cost of detonation

[Edited on May 2, 2011 at 10:27 AM. Reason : ]

5/2/2011 10:24:30 AM

Most N/A engines sluff off a little det...

5/2/2011 10:28:26 AM

Quote :

"^^ Well if you don't tune it then you're running leaner. less gasoline consumption so better mpg I guess at the cost of detonation"

how does having a different filter trick the MAF? wouldn't it be using more fuel with the added air?

5/2/2011 11:12:28 AM

In my experience tuning richer to match extra airflow just results in a more powerful machine with more usable power and better mpg, assuming you keep your foot out of it and your carb cruise circuit is setup properly.

[Edited on May 2, 2011 at 11:30 AM. Reason : in the case of a FI I doubt the air filter matters to cruise fuel consumption, ecu will compensate]

5/2/2011 11:28:35 AM

Quote :

"increased fuel economy at a cost of increased cylinder and ring wear. change your paper filter regularly and all will be right"

I'm gonna disagree with you. I've had a K&N filter on my Integra for over 150,000 miles (engine itself has 285k miles) and it runs just fine with no oil leakage or burning.

5/2/2011 11:56:42 AM

Yeah my thoughts too but i'm betting he drives a truck.

IMHO i wouldn't put a K&N on a truck, but then i also wouldn't care about 4-5 hp on a truck either.

5/2/2011 1:00:37 PM

^Yeh, I'm asking because I'm driving my Grand Marquis at the moment until I get a new car. My baby drinks so much gas it's not even funny. A guy at O'reilly's said he put one on his mustang and it helped him out...

5/2/2011 1:12:48 PM

but if the car is varying the amount of gas its injecting, and the maf is recording more airflow, doesn't that mean more gas consumption? in fact, if you look online you will find many accounts of people seeing increased fuel consumption with a k&n. unless someone explains to me why i'm wrong, it seems logical to me that gas consumption would increase.

and i get that the parts store guy may tell you he has saved gas, but he's also the type that will tell you driving with the tailgate down saves gas (it doesn't). i've heard that the k&n saves gas too, but i never believed it because it just doesn't add up.

am i wrong?

[Edited on May 2, 2011 at 1:45 PM. Reason : .]

5/2/2011 1:44:00 PM

It depends if its an entire cold air intake you're wrong because they manupulate ths size of the tube near the maf sensor.

If its a regular drop in filter the maf pretty much reads the same... you might get more airflow at a lower thottle angle though which may tell the ecu its at a lower load point which may run slightly leaner but that's a lot of maybes and mights for something pretty insignificant.

[Edited on May 2, 2011 at 1:55 PM. Reason : .]

5/2/2011 1:54:27 PM

but it's measuring density, not volume. if you manipulated the geometry ahead, that is going to be reflected in the reading of the maf because it is measuring the density (via how much energy the air absorbs) and the volume is still constant.

could you go into more detail with your response?

5/2/2011 2:22:19 PM

Mass Airflow Sensors are a thin wire that heats up and is cooled by the entering airflow and then the airflow is determined by the amount of voltage required to maintain its set point temp.

Having a larger diameter tube means it is effected by a smaller portion of the airflow and has to be re calibrated accordingly

http://www.kstech.biz/servlet/the-Legacy-GT-%28%2705-dsh-%2709%29/Categories

Using my car for an example you will notice that they offer

Stock size - good to 350awhp
73mm -good to 450awhp
83mm- good to 550awhp

Now that amount of "awhp" has nothing to do with the filter or how much air can flow through the pipe but how much air you can scale your MAF to measure through each one of these pipes.

If you did not re-scale your maf running the 83mm intake on the stock calibration would have your car running almost twice the AFR the car is shooting for because the sensor would only be metering a little more than half of what is actually making it to the engine.

5/2/2011 2:39:21 PM

If you improve airflow through the engine (intake or exhaust) you will improve fuel mileage, IF you tune properly for it. I'd imagine that the newer the car the more difficult that is?

5/2/2011 2:59:18 PM

ah, i thought they changed the geometry before the flow sensor and the diameter of the sensor was the same and the only effects could have been if flow was not yet fully developed. i didn't realize the MAF was inserted into the new tube.

so the real advantage would be from the new transfer table and air volume, not the filter.

[Edited on May 2, 2011 at 3:21 PM. Reason : .]

5/2/2011 3:17:06 PM

Filter does help VE but barely and it will cause knock if not tuned for in certain cars.

5/2/2011 3:23:01 PM

@ tr8tor: I don't think you're going to see statistically significant increases in gas mileage with just a K&N as opposed to the standard paper element filter. This is just the drop-in filter you're talking about, not a whole new cone filter/intake tube/etc., right?

Don't know how old your Grand Marquis is, but I imagine you ought to be getting on the order of 17-18 city, around 25 highway MPG, correct? I feel your pain (the Marauder is even worse, I get around 15 city/22 highway.)

5/2/2011 4:38:10 PM

^I'm not very car savvy but I think it would be the former, not the latter. And dude, I seriously think I'm getting worse gas mileage than what you listed. I feel like its downright horrible.

5/3/2011 1:24:52 AM

personally i prefer the AEM Dryflow.

Quote :

"If its for a gm, don't get it. The grease gets on the MAF senesor and fucks it up."

The oil can cause issues with the MAF sensor. However, the problem stems from the owner cleaning and OVER-OILING. There is no way there is enough oil on the filter from the factory to cause issues.

5/3/2011 10:25:17 AM

Buy a better mpg car. Ur mpg's won't change that much to matter at all.

5/3/2011 3:10:13 PM

get a throttle body spacer.

5/3/2011 5:05:55 PM

i can personally attest to the fact that K&N filters don't do a damn thing performance-wise on the grand marquis/crown vic. intake sounds different, but that's the end of it. just use the OEM paper filter

what mileage are you seeing right now?

[Edited on May 3, 2011 at 5:57 PM. Reason : ^ throttle body spacers also have a negligible effect with the weak ass 16 valve 4.6L]

5/3/2011 5:57:01 PM

Have you thought about the hydrogen mod shit.

5/3/2011 11:26:19 PM

^^haven't had the time to figure it out yet, I just know it's horrible. I'll report back after I find out.

^I have no idea what that is.

[Edited on May 4, 2011 at 10:04 AM. Reason : dummy]

5/4/2011 10:02:56 AM

what do you guys think of this?

http://www.knfilters.com/search/product.aspx?Prod=63-1126

the stock aircleaner/housing is just awful on sportsters!

5/4/2011 1:22:56 PM

Quote :

"I feel like its downright horrible"

so you haven't done any real calculations yet?

5/4/2011 7:27:42 PM

fwiw i never saw anything better than 18-20mpg with my crown vic

i have heard of people getting 25-27 with a grand marq though, due to a light foot and the 2.73 rear axle ratio

5/4/2011 8:37:36 PM

My parents have a '97 Crown Vic that I have driven a decent amount, and I can usually get 24-25 highway. Not sure if it's a 2.73 or a 3.07 though.

18-20 highway? Really? Damn, how hard did you drive it? I get consistent 21-22 MPG highway in the Marauder and that's with 100 lbs on the CV and 3.55 gearing.

[Edited on May 4, 2011 at 10:52 PM. Reason : f]

5/4/2011 10:50:46 PM

that's the result of all city driving and a heavy right foot

plus the PCM program was changed for increased power, etc.. not really a valid comparison but i thought I'd throw it out there. i miss that car

5/5/2011 12:56:03 PM

Oh, that's 18-20 mostly city? Well that's not that bad. I was talking highway.

5/7/2011 12:08:42 PM

My brother got a used jeep with a K&N filter already in it, he already had one so he gave it to me to stick in my jeep. Yes we both drive jeeps. Mine is a 1999 Grand Cherokee, with 114k. His is a 2002, 2WD, with about the same mileage, His being 2WD gets better MPG. Both have the 4.7 L V8. I have had that K&N filter in my jeep for about a year and my highway mileage has been around 17.5 to 18.4. I noticed it was pretty dirty and needed cleaning so I recently cleaned the K&N filter with the Recharger kit, before my regular trip back to school. I used the cleaner, rinsed, dried, then re-oiled. I arrived back in Cary getting 21.8 MPG on my Jeep. This in my opinion was valid evidence that new and clean K&N filters do improve gas mileage.

5/19/2011 9:43:20 AM

^one trip with lots of uncontrolled variables isn't really enough to make a final judgement. You'd have to do it a few more times under similar traffic and weather conditions. There's simply no way that the filter alone increased your highway gas mileage 15%.

5/19/2011 10:14:50 AM