TV mileage improvement-K and N filters

[cruiserpop]

My dad, who owns a 35-ft Bounder with Chevy triton has been bugging me to put in a k and n air filter. The motorhome crowd swears by  them, claims all up to 5 mpg increase in gas mileage. Bit the bullit, found  a place that sells them over the counter close by. paid the $45 for the filter for my  Durango, and did a LOOOONG trip up the east coast through the mountains. Avaraged 1.5-2 MPG increase over the mileage I've been getting. May not be much, but with gas prices what they are, every little bit helps.

[flyfisherman]

My dad, who owns a 35-ft Bounder with Chevy triton has been bugging me to put in a k and n air filter. The motorhome crowd swears by  them, claims all up to 5 mpg increase in gas mileage. Bit the bullit, found  a place that sells them over the counter close by. paid the $45 for the filter for my  Durango, and did a LOOOONG trip up the east coast through the mountains. Avaraged 1.5-2 MPG increase over the mileage I've been getting. May not be much, but with gas prices what they are, every little bit helps.

Interesting. What kind of a store sells them? We have something like Pep Boys and  Camper World, would wonder if they would have any information.


Fly

[pershingd]

I purcahsed mine at a local auto parts store. Pep Boys should have it, but I'm sure Camping world would charge a lot more for them than anyone else (if they carried them).

David

[cruiserpop]

got mine at advanced auto parts locally. check the k and n website.

[tlhdoc]

The K&N filters are not an RV item.  You can get them at most auto parts stores.  You need to be cleaned and re-oiled (not over oiled) to work correctly.")

[brainpause]

Glad somebody had some real-world gains. I took mine out. I couldn't really tell a difference, performance or gas-mileage or otherwise.

Larry

[SpeakEasy]

I believe the best way to improve your gas mileage is probably to slow down. I won't go into all the details, but I kept very close watch on my mileage on my long trip (4800 miles) in July. I kept notes on all sorts of variables like speed, gas grade, towing vs not towing, AC vs no AC, hills vs flat, and so on. The biggest improvement seemed to me to be consistently related to my speed. Slowing down even 3 or 4 miles per hour made a measurable difference.

[TheViking]

I had one too and could not tell much of a difference at all.  Plus, these types of filters need to be cleaned periodically and then re-oiled.  If you you put too much oil on them, it can screw up certain sensors in certain vehicles.  there are alot of things people say you can do to increase mileage, power, torque, etc. The best thing to do is research, I was always taught that dual exhaust and bigger exhaust pipes help the engine "Breathe".  This is for the most part true, however, in doing this you lose Low end torque by decreasing the engines back pressure, which is a pretty vital part needed for towing.  Research it before you run out and do something you will end up removing later.

[Billy Bob]

Now just think for a moment. The BIG 3 needs to increase gas milage in ALL their vehicles but they DON'T change to this air filter. Gee, I wonder why ? ? ?

[AustinBoston]

Now just think for a moment. The BIG 3 needs to increase gas milage in ALL their vehicles but they DON'T change to this air filter. Gee, I wonder why ? ? ?

They make money selling replacement air filters.  It's sufficiently lucrative that my car has two air filters - one for the car and one for the cabin. :confused: That air aways used to be clean enough to breath, why does it need a filter now?

I agree with your sentiment, though; there is a lot of junk sold out there that will "dramatically improve" gas mileage at little cost that the auto makers don't touch because there's no scientific evidence that they do anything but separate the gullible from some of their money.

Austin

[lwbfl]

I have to disagree, the big three have no intentions of really improving milage or they could very easily.  Computers control everything on a vehicle now, and with adjusting fuel delivery and spart timing, they could make them all get great milage.  For example, there are several companies that produce "super" cars by retuning computers and freeing up air flow.  They can almost double the tourqe and horsepower AND improve fuel economy at the same time.  The auto-makers are influenced by the millions made by the oil industry.

[mike4947]

Here's a few factoids on the subject:
 
There have been over 50 sutudies done on the K&N filters. At least two by RV magazines, multiple ones by car performance magazines, not to mention several comsumer advocate zines.
None of them reported increased mileage that could not be contributed to simply replacing a dirty air filter with a clean one of any type. Any testing done using first a clean Paper element filter and then a K&N type oiled filter showed no gain or lose of mileage. The participants did in over 50% of the subjects reports a "perceived" increase in power. But it could not be verified by dyno results and was reported as most likely caused by the fact the K&N filter was unsilenced compared to a stock paper filter. In other words, "it sounded more powerful".
 
Remember why the K&N filter ws originally developed. Way back when off road racers where having propblems with plugging paper filter elements. Even stacking three elements would block from the dust common on off road courses. K&N sovled their problems, but by allowing larger openings in the elements.
Larger micron filtration means larger particles go through the filter. With race engines that commonly get completely rebuilt after each race the small amounts of larger particles that enter do little to reduce performance over the course of a race.
 
BUT, for me the most damning information, that is supplied by K&N themselves about the so called "refusal of warranty claims by manufacturers" says that while they will write a letter to the company/dealer, and that's their limit of involvement and they list as their "Warranty" they are NOT responsible for any damage done by their filters and their warranty is STRICTLY limited to repairing or replacing their filter.
 
So if you are off road racings your vehicle, intend to rebuild the engine on an accelerated schedule, and/or monitor your oil for unusual particle concentrations of forgein matter by all means add a K&N.

[chasd60]

I have and do use K&N air filters. I doubted them for a long time with the understanding that you can get better performance with no air filter but the lack of an air filter allows contaminants into the engine. What a swap off huh?
 
I stopped doubting them when they produced filtration capacities and performance ratings rated against other filters. My gains have been less in the MPG improvements and more in throttle response. Air does not flow into an engine, it is sucked into the engine. Sucking air into an engine uses HP. If it is easier to suck air into the engine, you lose less HP and you might possibly feel a quicker response to pressing on the acccelerator pedal and/or better mileage.
 
First hand use and/or endorsement or lack of it is the best way to judge a product. Dynos' test for peak HP and torque but not engine rpm acceleration times.
 
As far as warranty replacement........ I know of many products that will refund you the cost of the product but will not warranty the application you are using the product on. Many motor oils do so. Why should they warranty the end product when you have the Moss-Magnusson Warranty Act. This Act basically states that you can use aftermarket parts on your vehicle and the original equipment manufacturer cannot void your warranty without proving that the aftermarket product caused the failure.

[wavery]

I have to disagree, the big three have no intentions of really improving milage or they could very easily.  Computers control everything on a vehicle now, and with adjusting fuel delivery and spart timing, they could make them all get great milage.  For example, there are several companies that produce "super" cars by retuning computers and freeing up air flow.  They can almost double the tourqe and horsepower AND improve fuel economy at the same time.  The auto-makers are influenced by the millions made by the oil industry.

Boy, I don't know where you are getting your info...... I worked as service manager for a large Chevy Dealership in Los Angeles for many years. My involvement with the manufacturer proves to "ME", without a doubt, that GM and all other auto manufacturers spend millions on research and development to produce a car that is balanced in performance, economy, style and compliance with government regulations. If the manufacturers are marketing a particular model car to be competitive in fuel economy, you can rest assured that they are doing everything possible to out-do all of the competitors. If they don't, they simply won't sell many of that model car.

The automotive market place is intensely competitive. Mileage is a huge concern with the consumer and if the manufacturers feel that they can sell more cars by unleashing known technology, trust me, they will do it.

The auto manufacturers don't care any more about the oil companies then the oil companies care about the auto manufacturers. The oil companies will sell all the oil that they can pull out of the ground, regardless of what the auto manufacturers do. Any idea of collusion between the two are pure fantasy IMHO. The auto manufacturers make their money by selling cars, not oil.

As far as these KN air filters are concerned, they have been around for many-many years. They have recently started marketing to the driving public as being a fuel saving and performance add-on for passenger cars, light trucks and RVs. Their claims are down right non-sense IMO. The fact is, you will definitely void the warranty on your vehicle by tampering with the intake system on your car. In fact, in California (and many other states), it is illegal to tamper with the intake system because by doing so, you are tampering with your emission system.

The ONLY way that you could increase performance/mileage by altering your intake is by increasing the effective fuel to air ratio in a manner that would FORCE more air down the intake. This is commonly done by adding a supercharger or turbo-charger. The cost of doing that would far out-way the potential savings in fuel. In fact, even by adding these devises, you will only increase mileage under extreme conditions like racing or pulling up mountains at high RPM. You would see little to no savings or performance or economy increase under normal driving conditions.

As stated earlier, you can increase you mileage by simply replacing a dirty air filter. When the air filter gets dirty, it changes the air/fuel ratio and decreases efficiency. The computer in the car can compensate for a small amount of restricted air flow. After that, it's like driving your car with a a bag over the air filter. I also agree with the fact that the vehicle "Sounds" more powerful because you can hear the un-muffled intake. It's an illusion, my friend, just an illusion. The manufacturers design the air filters so that they are not that noisy for a reason.

The idea of a custom air filter giving you a performance or fuel economy benefit is such non-sense that I feel silly spending so much time disputing it. There-in lies the problem......... So do many others!

[chasd60]

The fact is, you will definitely void the warranty on your vehicle by tampering with the intake system on your car. In fact, in California (and many other states), it is illegal to tamper with the intake system because by doing so, you are tampering with your emission system.

That statement is not based upon fact but an opinion.
CARB approved modifications will not void any emissions related tests and it is not ILLEGAL to tamper with the intake system any more than it is to do so with the exhaust. I have affixed CARB stickers to many vehicles for aftermarket items. CARB=California Air Resources Board
 

The idea of a custom air filter giving you a performance or fuel economy benefit is such non-sense that I feel silly spending so much time disputing it. There-in lies the problem......... So do many others!

And yet the topic got you to respond....Interesting....
 
My reasoning stands and I did not see where you have supported your point based upon personal experience. Manufacturers typically design for the masses and won't spend additional funds for the gains that some of us have actually gained. Sometimes the increase in tooling costs to optimize the performance is not justified as acceptable. They are looking for a certain % markup and trying to compete with other manufacturers at the same time.
 
1988 Chevrolet Sprint. EPA 60 mpg highway
2006 Honda Insight Hybrid EPA 66 mpg highway
Looks kinda like someone dropped the ball if that is all we have gained in 18 years, huh?
 
 
cruiserpop calculated his gains and they were not perceived.