OT : K and N air filters for cars

They make a lot of bogus claims…

– Last Updated: Dec-15-05 10:41 PM EST –

...and the truth is that they don't filter as well as a paper filter until they get dirty. When you clean and re-oil it, you need to be careful with amount of oil you use. Any oil that gets drawn into the intake can damage the mass-airflow sensors used in most newer cars.

In the Carburetor days…
Back in the “good ole days” of cars with carburetors, the air cleaner being clean or dirty would make a difference in gas milage. When the air cleaner was clean, the air flow thru the carb is what pulled gas into the air, as it passed thru the carb venturi. When the air filter got dirty, a vacuum would form in the air intake, and suck more gas thru the carb. This cause worse gas milage on an engine with a carburetor.



With the new fuel injection systems, the computer monitors the oxygen in exhaust, air & coolant temps, and the air flow. So regardless of whether or not the air cleaner is flowing a little, or a lot of air, the computer keeps the fuel to air mixture regulated for an optimum mixture.



BUT… if the filter is dirty, it will pass less air, and give less power.



My beliefe is (IMHO) that a K&N filter will not improve gas milage, but can give you more power by allowing the air into your engine easier. Flowing more air, will tell the fuel injection to spray more fuel, and then give you more power.



If you drive the engine sensibly, it “should” still give about the same gas milage, but if you need the extra power, like for towing, or for a performance car, then I think a K&N can be of some help.



You need to be the one to make the final decision. Thanks for the tips on not over oiling the filter when cleaning. I would not want to have to replace the Mass Air Flow Sensor!

Good post
That’s always been my thinking as well. Whether the restriction of airflow is happening via a possibly-restrictive air filter or a FI throttle butterfly it’s basically the same thing from the point of view of the engine itself. Until the throttle is getting close to wide open anyway.



Mike

K&N for racing!
If you are a racer then use a K&N filter. You are better off with your old paper filter in stock applications. I’ve been racing for the past ten years go-carts, motorcycles, cars, ect. and wouldn’t think of using any other kind of filter. But for the everyday motorist the goood old paper filter is your best bet.Proper vehicle mantinence re: tuneup, oil changes, even running the right air pressure will improve your gas mileage

K&N in my Ranger
Believe it or not, I actually lost 1.5mpg over the stock filter in the ranger equipped with the 2.3 4cyl. I ran four tests over a full tank of gas and highway driving (each time) and sure enough…mileage was less with the K&N.

If there was any power increase I sure couldn’t feel it.

K & N filters
The maximum power increase you could get with any filter would be - whatever power increase you’d get by removing the filter entirely.



It ain’t gonna be huge but there should be some improvement with a K & N because there’s a small reduction in intake system restriction and therefore your engine gets a smidgen more oxygen.



Vehicles with fuel injection can easily automatically adjust for this change in air (and add a smidgen more fuel). If your vehicle has a carburetor (what’s that?) and if you are unlucky, then it could potentially make the vehicle run a touch worse.



I always remember putting K & N’s on my Kawasaki 500 2-stroke in the 70’s and the bike clearly made more powr immediately - and more (intake) noise too.

Thanks toco, thats all I need to hear.