question about K&N air filters

[Dave McFly]

I was just giving 'Monty' a good cleaning inside and out and decided to replace the air filter and to my surprise my dad installed a K&N air filter inside the box where a OEM filter usually lives. I heard these filters are reusable up to a (highly questionable) 1,000,000 miles. does anybody here have one or had one in the past in their car/cars? if so what do you do to clean them up so they are as good as they were new? and I heard they add SOME horses and improves your MPG SOMEWHAT. is this just or do they really do as they say they do? If so how much on average do they add I am sure that it depends on the make/model of the car and the engine in said car. my car has a 3.4 liter V6 rated at (under rated if you ask me ) 180 horses. and with this engine I am supposed to get 19 city 30 highway. what do you think this filter will do for those numbers?

[Mindz]

probably won't see much unless you swap the exhaust. maybe 1-2 mpg more and about 3hp I would imagine. The filter does let the engine breathe slightly easier. I replaced my airbox with a filter on my eclipse and it did about that. (140 hp at the crank stock).

You won't notice a difference unless you drive the same way before and after. It doesn't make that much of a difference unless it's paired with other "breathe easy mods"

[theholycow]

They can not increase MPG unless you drive really fast, high RPM, wide open throttle all the time -- and if you drive like that you don't really care about MPG anyway.

They also can't increase performance unless you drive like that. At anything less than WOT@high RPM, the air is not restricted by the air filter; and on a stock vehicle, unless its engineers were severely negligent, the air filter won't restrict air flow even then. No, you have to have done other upgrades too, as the others above describe.

As for cleaning and reusing, it ought to last through repeated cleanings and re-uses until it falls apart. The one I had some years ago seemed very durable, and if they all are then I expect they would last longer than the average car. Be absolutely sure not to over-oil it, as that is known to kill MAF sensors.

[The_Stache]

Originally Posted by theholycow

They can not increase MPG unless you drive really fast, high RPM, wide open throttle all the time -- and if you drive like that you don't really care about MPG anyway.

They also can't increase performance unless you drive like that. At anything less than WOT@high RPM, the air is not restricted by the air filter; and on a stock vehicle, unless its engineers were severely negligent, the air filter won't restrict air flow even then. No, you have to have done other upgrades too, as the others above describe.

As for cleaning and reusing, it ought to last through repeated cleanings and re-uses until it falls apart. The one I had some years ago seemed very durable, and if they all are then I expect they would last longer than the average car. Be absolutely sure not to over-oil it, as that is known to kill MAF sensors.

Like THC the great thing about them is when it gets dirty you just clean it instead of going and buying another filter. Yes it will help your engine breath better but without a change in tune the engine doesn't compensate for it (beyond the currently loaded maps) so you wont really see a difference.

That said its always good to have a quality product performing the best it can, even in a mundane use.

[lafountain]

I was just about to ask about these myself, but found this thread. On a Mazda forum my wife and I look at once in a while, someone with a Mazda3 states that after they put in a K&N Air Filter that they gained about 20 miles per tank of gas. Does this sound reasonable, cause if it is, I will likely go and put one in my 95.

http://www.mazdaforum.com/m_78711/tm.htm

[theholycow]

If they drive at high RPM with wide-open throttle all the time, the K&N may be the cause of their extra 20 miles. If the car was designed by idiots who chose the wrong filter to specify, the K&N could have helped. If the car has been modified significantly, the K&N could have helped.

If it is stock and driven at less than full throttle, the K&N probably did not cause their increase.

They didn't even state any actual fuel economy increase, just that they went 20 miles more on the tank -- which is pretty easy to do just by waiting another 20 miles unless they always run it out of gas and carry a gas can to get them to the next gas station.

It's a 6% increase in miles per tank according to the numbers posted in that thread. You could probably get the same by increasing your tire pressure (if it doesn't make handling bad and if it doesn't exceed the tire's rated maximum). In your 1995 3.8L Camaro you can probably get the same increase by shifting earlier (if it's got a manual transmission); you're probably not using as much of the low-end torque as you should use for best fuel economy.

[Dan]

K&Ns are great filters. I have one on the goat and the first one I ever had on an old cutlass caused me to jet up the carb because it started lean surging after I put it in so it definitely flows more air. As for cleaning it get a cleaning kit which will come with a cleaning solution and a can of oil. Never used compressed air to dry it, you can blow the cotton right out of the filter. Also don't put too much oil on it, the oil will spread out.