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K&N Airfilters and gas mileage?

jcook90

Turbo Monkey
Mar 3, 2006
1,211
0
Connecticut
Anyone got one? Their website claims that they boost gas mileage by straightening the airflow, which makes sense, I was just wondering what the real-world gains are
 

ultraNoob

Yoshinoya Destroyer
Jan 20, 2007
4,515
1
Hills of Paradise
Actually lost mileage in my Gf's car. A couple of things happened too.
1: Oil from the filter built up on the intake air temp sensor causing incorrect data sent to the computer
2: Throttle bore and throttle plate got dirtier faster (dirt sticks to oil from filter)
3: Reduced fuel economy... my theory below
As more air is introduced into the motor, the ECU (engine control unit) by way of the oxygen sensors, will sense a leaner air/fuel ratio. It will then respond by adding more fuel (keeping fuel injectors open longer) to maintain it's desired air/fuel ratio. Power will slightly increase and should only manifest itself at WOT (wide open throttle).

Edit: Most washable air filters will allow more air into your engine, but as a trade off it will also allow more dirt to get in as well. More dirt into your engine = reduced engine life
 

BMXman

I wish I was Canadian
Sep 8, 2001
13,830
0
Victoria, BC
Anyone got one? Their website claims that they boost gas mileage by straightening the airflow, which makes sense, I was just wondering what the real-world gains are
oh and BTW...a good air intake will improve gas mileage but you have to buy the right one for your car...D
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
14,370
945
My own world inside my head
If you get a complete INTAKE system, then maybe; but just replacing your paper air filter with an K&N (or whatever) will most likely will not.
This is actually a true statement. If you dont change the resitrictive nature of the cars Intake system with the use of Baffles fopr sound reduction and such, you dont get any inprovement with the airfilter itself, And then even with the entire system, you dont see a Major Improvement untill you flash the PCM to match the now added amount of air, until you do so the vehicle, fuel injection anyways, will run lean, which in turn will raise cylinder temps, raise NOx emissions, and wear your engine faster.
 

stevew

unique white person
Sep 21, 2001
33,304
3,928
My brothers Dodge performs much better with a filter from a Volvo semi.

Improved mileage/less lag.
 

Austin Bike

Turbo Monkey
Jan 26, 2003
1,559
0
Duh, Austin
Rednecks don't need gas caps, they don't worry about gas evaporation because their buddy bush has supplied us all with cheap gas. Remember that?
 

eaterofdog

ass grabber
Sep 8, 2006
7,685
819
Central Florida
Not much difference in the gas mileage. They will give you more power on the top end, but they need to be washed and oiled monthly, which is a pain in the rear. If you don't, you will be getting dirt in your motor.
 

Upgr8r

High Priest or maybe Jedi Master
May 2, 2006
942
0
Ventura, CA
I tried one on my 2005 Dodge Dakota V8. Initially, it increased power (slightly) but didn't do a thing for gas mileage. As the filter got dirty, which it did rather quickly, the performance and mileage statred dropping steadily. The cleaning procedure is such a pain in the rear that I gave up on K & M and went back to a stock filter. I'd rather find a high quality paper filter.

My advice based on experiance is DON'T DO IT. It's not worth it