K&N Air Filters?

[Mr. W.]

Good afternoon. A quick search of the forums didn't return any results, but I'm sure I've read that some of you are using the K&N premium air filters in your tow vehicles. Can anybody attest to what kind of fuel economy benefits are realized with these filters? I can buy a regular pleated filter for my vehicle for $7, whereas a K&N costs $40. Is it worth the premium price?

[Donna D.]

I believe so yes, but my experience has been with hot rods, because of the increase in HP...and you absolutely want to stay off dirt roads.

[Mr. W.]

...and you absolutely want to stay off dirt roads.

...because they don't trap fine dirt, or because they trap it so well that the engine will starve for air?

[jasoncarder]

I've used K&N filters in our vehicles for several years, and although they haven't provided a noticable improvement in gas mileage or performance, I figure they're still a worthwhile investment. Why? Because a paper filter lasts, on average, 12000 miles or so, while the K&N filters have a lifetime guarantee. As long as you take them out and clean them, they will pay for themselves after a few years.

[daveterp]

I put a K&N filter on my '00 Cherokee 18 months ago, improving my mileage by about 4%. A 4% reduction in my gas bill certainly justifies the extra cost to me. The improvement does seem to vary from make & model though. My neighbour tried one on his F150 and couldnt see any improvement at all. He kept it though cause he likes the wind tunnel noise it makes.
Dave

[Roger H]

The benefits of K&N are controversial at best. Across a variety of forums the debate rages.

I put a Fuel Intake Performance Kit (FIPK) on my Excursion V10 two years ago and experienced a 2 mpg increase in mileage across the board. There's no logical reason for it since the actual airflow is dictated by the Mass Airflow sensor, but the fact is that there's an increase. I put a standard K&N replacement filter on my Tundra and haven't really noticed much of an increase.

My wife bought me an FIPK for the Tundra that arrived just today and I'll be installing in about 20 minutes.

There are a couple of issues to watch for. First, you need to clean and oil them about every 6 months. Second, if you plan on doing a fair amount of dusty or gravel road driving, don't even think about it. You need the filtering capacity of a high quality air box filter. If you do normal driving on normal hard-surface roads and there's not a significant amount of dust, the K&N may work for you. I'd recommend the FIPK to see any real gains in power or mileage though, and they're about $220 with the filter. Are they worth it? Probably not, but they sure look cool under the hood! And that 5% fuel economy increase is nothing to sneeze at either, particularly as gas prices continue to climb. And, if you keep the vehicle long enough and change the air filter regularly, the few dollars you don't have to spend on filters will pay too.

BTW, I'd never use a $7 filter. They're almost as bad as no filter at all, although I guess they do keep out June bugs and butterflies... Get the premium stuff. They're worth the money. I use K&N Oil Filters exclusively, and when I don't have them, I use Wix.

Roger

[John Perry]

I started using Mobil One and a K&N at the same service. The gain has been about 3 MPG.
From 23 to 27 average MPG. Is it the oil or the filter? I don't know, but I am happy.
I live in the high deset and was changing the air filter quit often. I have saved the price of 4 Toyta filters since installing the K&N.

John

[Brian B-P]

I used a K&N on my Tercel for over 300,000 kilometres (200,000 miles), and I have no complaints. I switched to it at my first air filter change, for cost savings as Jason described. I used to track fuel economy closely, and drove that car aggressively, but do not recall improvements (or degradation) in either fuel economy or performance... but that's not why I put it on. It was a direct replacement in the stock housing for the original filter.

I was never as concerned about dusty situations as others seem to be. I just cleaned it when it needed it. If cleaning out dirty filters and re-oiling them sounds unpleasant to you, I suggest sticking with original-equipment spec stock paper filters.

Whether or not you get an improvement from an air filter change or other changes in the air intake system upstream of the throttle depend on whether they are limiting factors in that particular engine installation's performance. I noticed one ad from a diesel performance accessory company which listed power gains for their products for various years of trucks (always power, not economy...) and the newer the truck the less the gain, presumably as the manufacturers have optimized the stock system.

[Roger H]

OK! Got the K&N FIPK installed on the Tundra last night!





I switched to Mobil 1 for all of our cars a couple of years ago. When I traded cars every couple of years, I didn't really care. I'm planning on paying off and keeping all three of the ones we currently have until it's not cost effective any more, and I see that as waaaay down the road!

Roger

[Kurt & Ann K.]

In the Toyota dealership shop where my son works, every car which is K&N equipt that they see for service, is choked for air. It appears that people service the filter the first time, then neglect it.
The concept sounds good but in practice the mileage goes down hill due to neglect.
If there were a lifetime, no maintenance filter, that would be another matter.

Kurt & Ann K.

[Donald Stahl]

We drive a 2002 Odyssey, bought it new. Understanably, a new engine will not get very good mileage until the engine has been well broken in, which, on our vehicle was around 15 to 20 thousand miles. I did install a K and N air filter and subsequently gotten around 2 miles per gallon better highway mileage. As has been mentioned, the filter is for the life of the car, can be cleaned with an inexpensive solution, which will eventually pay for itself.

I also changed from oil to a high grade synthetic with the same viscosity. That made even a more significant difference in mpg. Understand, one must go easy on the accelerator, try to time the traffic lights to avoid stops. Back off the gas pedal when a red light is anticipated. Maintain proper tire pressure.

Setting the cruise at a continuous highway speed is the best determinant. Our van is rated at 25 mpg highway by EPA. What was achieved on a recent trip from Show Low, Az to Flagstaff, Az, and back, cruise set at 65 mph, was the best yet - 32.3 mpg. Around town with all the stop and go - 23 mpg.

Fast accelerating and fast stops would probably negate benefits considerably.

Don

[Roger H]

In the Toyota dealership shop where my son works, every car which is K&N equipt that they see for service, is choked for air. It appears that people service the filter the first time, then neglect it.
The concept sounds good but in practice the mileage goes down hill due to neglect.
If there were a lifetime, no maintenance filter, that would be another matter.

Kurt & Ann K.

Everything needs service. If you put a K&N on, you have to recognize that it's a service commitment. I know people who never change their oil in a Toyota too. That's not a shortcoming of the equipment.

I noticed this morning that while it used to take several crank-overs to start the 6 cyl (and yes, it was JUST tuned up), it fired this morning on the first crank-over. I was really amazed at that difference.

It does, BTW, come with a "million mile warranty" provided that it's cleaned regularly.

Roger

[Donald Stahl]

Kurt and Ann,
I know people who let their car mileage rack up to 40,000 or so and have never changed the oil ! The transmission? Forget that ! One person I know NEVER checks the air pressure in the tires. Last time we visited, I checked them - they all were 20 lbs., one at 18 lbs. The single lady who owned the car said that checking tire pressures was a 'man thing.' Many people will neglect proper maintenance. As Roger said, that is not the fault of the product. My two cents. Don

[Lizbeth]

How exactly does one clean (and oil?) a K & N filter? My used jeep came with one and I'm sure it needs cleaning. It's a V8 so it needs all the help it can get in the gas mileage department.

[Roger H]

Just take it off and throw it in the dishwasher.

JUST KIDDING!!!

You buy a K&N filter cleaning and oil kit. You use the cleaner as directed and spray it onto the filter. Let it sit the required time, and hose it clean. Let it air dry (DO NOT use compressed air) and then use the appropriate amount of oil on it as directed. It takes a couple of hours, (most of that drying time) and you're good to go again.

You should clean your filter about every six months. Don't use too much oil as the oil can foul mass airflow sensors if there's an excess.

Roger

[colin k]

I used to run a K&N in my Tacoma until i decided to pull off the rubber intake tube between the filter and the intake manifold. I discovered very fine silt/dust that got past the filter. I returned the filter and went back to the factory filter. K&N suggests to run a prefilter as well as the regular K&N filter if you want to keep out the dust.
I found the K&N made no difference in performance or fuel economy.

[Roger H]

I used to run a K&N in my Tacoma until i decided to pull off the rubber intake tube between the filter and the intake manifold. I discovered very fine silt/dust that got past the filter. I returned the filter and went back to the factory filter. K&N suggests to run a prefilter as well as the regular K&N filter if you want to keep out the dust.
I found the K&N made no difference in performance or fuel economy.

Colin, I think everyone pretty much agrees that K&N isn't a good choice for running in dusty conditions, and probably half of the folks who use them report that they don't do much. I got about 2mpg gain on my Excursion. It'll be interesting to see if there's any improvement with the Tundra V6. The dyno charts claim a 5hp boost with the K&N, not enough to set you back in the seat by any means, but nothing to sneeze at when you're towing a Bigfoot 17 with a 3.4l V6 either. Every little bit helps.



Roger

[Brian B-P]

I'm having difficulty reconciling observations that the filter doesn't do much for economy, and more than one quote of a 2 MPG gain. That's about a 10% improvement in fuel consumption, which is enormous. I would not expect such a gain from an air filter change, and I can only guess that the gain comes from other changes made at the same time.

[Roger H]

I'd guess, Brian, that a lot of the improvement has to do with both driving style and how much constriction there is in the stock intake tubing compared to the K&N intake replacement tubing. Obviously, if the stock equipment is free-flowing and doesn't have a significant constriction on airflow, the K&N FIPK won't help much. Recognize also that K&N filters are available merely as drop-in replacements for the stock filter media. I didn't notice any gains at all with just the stock filter replacement. The gains I recognized on the Excursion are with the installation of the FIPK. The HP gains claimed by K&N are at fairly high RPMs.

I'm hoping to see similar gains in the Toyota.

Roger

[Lizbeth]

Just take it off and throw it in the dishwasher.
Roger

Ok.