Will A K&N Filter Affect My Vehicle's Fuel Economy?
is a relationship between air filter restriction and mileage.
The theory behind this is simple, the harder an engine has
to work to suck air through the intake tubes and air filter,
the more gas gets wasted in the process. Many K&N users
report an increase in their fuel economy after beginning to
use our air filters, as noted on our testimonial page. However,
these experiences do not mean you will also experience a change
in your mileage. We certainly understand why it is theoretically
possible for a consumer to experience a mileage increase after
installing a K&N air filter or intake system, however,
we do not go so far as to make a general claim that our air
filters and intake systems will provide an increase in mileage.
It is virtually impossible to make sweeping and general claims
about mileage. Even the EPA fuel rating numbers for new cars
are often not representative of the mileage you actually experience.
There are many variables that affect mileage such as: tire
inflation, the type of fuel, weather, elevation, the speed
at which you drive, the gear in which you drive, the speed
with which you accelerate, engine maintenance, excessive idling,
cruise control, the grade of motor oil you use, and of course,
the condition of your air filter. In short, mileage is complicated.
K&N filters are less restrictive than disposable paper
or synthetic air filters and K&N Intake Systems are less
restrictive than the factory installed air path. So K&N
filter technology could be an important tool, when combined
with other elements, to help keep mileage as high as possible.
Oh yeah, there's one more limitation imposed by science. If
you take advantage of added power by driving more aggressively,
you will reduce mileage. You cannot have your cake and eat
Increase In Horsepower Should I Expect From A K&N Replacement
direct replacement filters which install into your vehicle's
factory air box can provide an increase of between 1 and 4
horsepower. Results will vary depending on your vehicle, driving
habits, load on the engine (towing for example), existing
air system restriction, and other factors.
Increase In Horsepower Should I Expect From A K&N Air
makes several different types and configurations of performance
air intake systems. Depending on the year, make, and model
of your vehicle, only one style of intake system may be available
for that vehicle. All of our intake systems are dyno-tested
and guaranteed to increase your vehicle's horsepower. Instead
of making a general claim, we publish estimated intake system
horsepower increases for many part numbers and vehicles. To
see estimated power gains of specific air intakes for specific
vehicles, enter the part number in our part search or look
up a specific vehicle in our application search.
How Often Do I Need
To Clean My K&N Air Filter?
have not experienced a decrease in mileage or engine performance,
chances are your filter is fine and does not yet need cleaning.
To be more specific, the filter does not require cleaning
if you can still see the wire screen on the entire air filter
regardless of how dirty it may appear. When the screen is
no longer visible some place on the filter, it is time to
clean it. When used in normal paved road, street or highway
conditions, our replacement air filters that fit in the factory
air box should require cleaning every 50,000 miles and our
large conical filters on an intake system should require cleaning
every 100,000 miles. When used in dusty or off-road environments,
our filters will require cleaning more often. We recommend
that you visually inspect your filter once every 25,000 miles
to determine if the screen is still visible.
Can I Tell The Size Of The Engine In My Vehicle?
America: Most vehicles have an emissions decal placed either
on the backside of the hood, on the radiator core support,
or on the air box (the box that holds the air filter in place).
Your engine size should be shown on the decal (4.0L for example).
If you can't find the emissions decal you may also find the
engine size printed on the decal under the hood that shows
your engine's belt routing. You may also write down your Vehicle
Identification Number that is stamped visibly near your driver's
side dashboard top and listed on your vehicle registration
certificate. This number can then be entered on K&N's
part search by VIN webpage to find engine size as well as
products for your vehicle. You may also contact your local
A K&N Filter Give My Engine Too Much Air Flow?
engine can only draw in a certain volume of air depending
on the engine's size (measured by such things as bore, stroke
and number of cylinders). Vehicles are designed to accommodate
large changes in air pressure so they can operate at sea level
or at an altitude of 14,000 feet. Engine computers adjust
the amount of fuel required as a result of changes in air
pressure (density). Air filter restriction when the filter
is new and especially as the filter loads with dust will result
in lower air pressure and availability similar to being at
a high elevation. High-flow air filters that were invented
by K&N were designed to reduce the work necessary to pull
air through the filter and to increase air pressure. Increased
air pressure is one of the key elements in producing more
Using A K&N Direct Replacement Filter Void My Factory
against federal law in the United States for a manufacturer
to require the use of a specific brand of air or oil filter
unless it provides a replacement air or oil filter, free of
charge, under the terms of the vehicle warranty. For a more
thorough discussion of this law known as the Magnuson-Moss
Warranty Act, see our Vehicle Warranty Section of our Air
Filter Facts page, and our Letter Regarding Vehicle Warranty
and K&N Replacement Filters.
Installing A K&N Performance Intake System Void My Factory
K&N air intake systems are warranted for 1,000,000 miles
which exceeds the warranty offered on the original factory
intake system. The installation of an air intake system should
not void your factory warranty. It is never a bad idea to
contact your local dealership and ask them before purchasing
the new K&N system whether they will object. If they tell
you an air intake system will void your vehicle warranty,
please contact us and we will speak with the dealership directly
to clear up the misunderstanding. Another idea would be to
contact a different dealer who may have a different policy
since many dealerships actually sell K&N intake systems.
As an additional level of comfort, we also offer our Consumer
Protection Pledge. It takes customer service to an even higher
level by giving you confidence that when you buy K&N you
get on-going support from a team of professionals who will
talk directly to dealerships to resolve any questions that
may come up.
K&N Air Filters Come Pre-Oiled Or Must They Be Oiled Before
all K&N air filters come pre-oiled and ready to use. The
filter oil we use is red. A new oiled filter will appear red-pink
in color. Some crankcase vent air filters come unoiled, however,
they come with a small packet of K&N filter oil so they
can be oiled before use. There are also a limited number of
filters with specialty uses which are not pre-oiled. These
items will be clearly marked as unoiled. Using an unoiled
K&N filter will greatly reduce the filter's efficiency
and void our product warranty on filters that come pre-oiled
from the factory. If you receive a filter that is packaged
in its cellophane wrapper and is unoiled, contact K&N's
Customer Support department at (800) 858-3333.
A K&N Air Filter Be Made At The Factory For Any Application?
has an active Custom Air Filter Program to meet the needs
of consumers with special filtration needs. We offer thousands
of possible configurations of custom filters, in different
shapes, dimensions and heights. Click here to read more.
Filter Came With A Tube Of Sealing Grease. How Important Is
rather important. It helps to maintain a seal on an uneven
air box surface. If sealing grease is unavailable, white lithium
or synthetic grease will work just fine. Petroleum-based products
are not recommended.
K&N Filters Emissions Legal?
direct replacement filters are emissions legal. They perform
the same function as other types of disposable filters and
fit right into the factory air box. K&N's custom, universal
or conical air filters are not legal for street use in California
or other states that have emission control standards. However,
if the intake system you are attaching a K&N cone filter
to is CARB exempt, the K&N cone filter will not change
that status and will be part of the exempt system. Check your
local laws if you are unsure what modifications may be allowed
on your vehicle.
K&N Performance Air Intake Systems Emissions Legal In
systems are legal in most states because most states do not
have regulations governing them. So this question really has
to do with California and other states that have emission
control standards. In order for an intake system to be legal
in these states, it must receive an Exemption in the form
of an EO number from the California Air Resources Board (CARB).
To further complicate matters CARB exemption is issued only
for specific part numbers used on specific vehicles. That
means a part number can be CARB exempt for some vehicle applications
and not others. There is no such thing as CARB Pending. A
particular part number on a particular vehicle is either exempt
or not. The best way for you to determine the status of the
part number you are interested in for your vehicle is to look
up the intake systems available for your vehicle in our vehicle/part
search engine and check for CARB exemption. If you are unsure
whether CARB exemption is required for a part to be legal
in your state, check with your local or state motor vehicle
or emissions agency.
K&N RK-Series Custom Air Cleaner Assemblies Emissions
for motorcycle intake kits are the same as for air intake
systems. Please refer to Question 13 above. Some RK-Series
assemblies for specific motorcycles have received CARB Exemption,
others have not. The best way for you to determine the status
of the part number you are interested in for your motorcycle
is to look up the parts available for your motorcycle in our
vehicle/part search engine.
Do I Clean A K&N Air Filter?
K&N Filter Care Service Kit, available at all major auto
parts stores and a low pressure nozzle-free garden hose. A
filter cleaned with K&N cleaning products will ensure
a lifetime of performance from your air filter. Instructions
for cleaning your K&N air filter are on our Air Filter
Cleaning Instructions page.
Much Oil Should I Use To Re-Oil My Filter After It Is Cleaned?
to our air filter cleaning and re-oiling procedure for details
on how to properly oil your filter once it is clean and dry.
For recommended oil quantity by filter part number, enter
the part number in the "Search by Part" box on our
Application Search Page and the factory oil amount will be
I Use Anything Other Than K&N Cleaner And Oil?
results, we recommend that you use K&N air filter oil
and K&N air filter cleaner. K&N air filter oil is
a special compound which forms a very efficient tacking agent
that helps capture dust. Our cleaner is a non-detergent degreaser.
Petroleum products such as transmission fluid and motor oil
will soften and destroy the rubber sealing edges. Harsh solvents
and gasoline will harden the rubber seals causing the filter
to distort (shrink). A mild detergent can be used in a pinch,
but care should be taken to fully rinse it out. Rinsing detergent
out of a filter is similar to getting soap out of a sponge;
it's not that easy to do. Always make sure the filter is dry
I Use Compressed Air To Dry The Filter Faster?
can blow the filter material right out of the wire mesh and
ruin the filter. Pick a nice day to clean the filter and let
it dry naturally. A low pressure air flow such as from an
industrial drying machine or blow dryer will help the filter
dry more quickly.
I Brush The Wire Screen With A Toothbrush To Get All The "Crud"
could tear up the cotton gauze.
Is The Micron Rating And Efficiency Of A K&N Air Filter?
are not measured by micron size. As an industry standard,
air filters are tested in accordance with the ISO 5011 test
protocol to measure capacity (the physical amount of dust
a filter can hold before cleaning is necessary) and efficiency
(the filter's ability to trap and hold dust). See technical
service bulletin 89-5R from the Filter Manufacturer's Council.
The dust selected for the test contains a specified distribution
of different particle sizes according to ISO standards.
of the two most commonly used types of ISO test dust for air
filters is as follows:
COARSE TEST DUST
FINE TEST DUST
Size in Micrometers (Microns)
by Volume (+/- 3%)
Size in Micrometers (Microns)
by Volume (+/- 3%)
has demonstrated that on average, K&N replacement air
filters and air intake systems have a cumulative or Full Life
filtration efficiency of between 96 and 99%. Different filters
test at different efficiencies due to changes in their shape,
surface area and relationship to the direction of air flow
through the factory air box or test housing. Like most air
filters available in the USA, our filters will provide all
the engine protection you need.
Are The Air Filtration Requirements For My Vehicle?
is no published requirement for vehicle filtration. Car and
truck owner's manuals are silent on the issue and you will
find very few companies that even credibly discuss filtration
efficiency. We believe this demonstrates that most air filters
sold today provide adequate levels of filtration. Particularly
when compared with the filtration provided by fuel and oil
Airflow Means You Are Letting More Dirt Through, Right?
testing measures the percentage of dust retained before the
filter reaches a terminal test pressure, often 10" of
restriction above initial restriction. We use airflow as a
simplified term to explain a more complicated physical process.
The more precise description is restriction: K&N air filters
create less restriction which helps an engine run better.
An engine will only use the air it needs and our air filters
do not result in an engine using more air than necessary.
Rather, they result in the engine experiencing less restriction.
The terms airflow and restriction are inversely related. Our
air filters provide either less restriction at a fixed airflow
rate; or more airflow as a fixed level of restriction. In
neither case is more air being used than necessary.
I Know The Dimensions Required, Do You Have A Clamp-On Air
Filter For My Special Application (Snowmobile, Tractor, Small
a powerful tool we have developed for just that purpose. You
can search our filter catalog by dimension and/or shape on
our Filter by Dimension Search page. We make hundreds of specialty,
custom and racing filters for just about any need. These specialty
filters come in many shapes, dimensions and sizes. Some of
them have angled or offset flanges to fit unique space requirements.
Another way to browse through our specialty, custom and racing
air filters is to visit our universal air filter page. If
none of these meet your needs our Custom Air Filter Program
may be able to help.
I Install The Largest K&N Filter That Will Fit In My Race
existing K&N filter is large enough to provide negligible
restriction, a larger than required filter will not affect
the amount of air an engine can take in, however, it will
lengthen the filter's service interval. A longer service interval
can be an important factor when racing in dusty, dirty environments.
A K&N Filter Cause My Vehicle's Mass Air Sensor To Fail?
is both impossible and ridiculous.
impossible because we know that the oil treatment on our cotton
is very small (usually less than 2 ounces). Once the oil is
properly and evenly absorbed through the cotton, no oil will
come off, even under extreme engine conditions. It is ridiculous,
because no dealership or service provider has ever been able
to provide us with evidence to support this "myth,"
and in fact, our investigations have revealed that even authorized
dealerships are simply speculating and do not have the test
equipment necessary to know whether the sensor has failed
or why. It is even more ridiculous because some car manufacturers
use and sell air filters treated with oil on a regular basis.
There are also major brands of disposable air filters that
are treated with oil. We all use oil for the same reason,
it helps in the filtration efficiency of an air filter. For
more information on this topic including videos, see our Mass
Air Flow Sensor Statement page. Out of the millions of air
filters we sell, we only receive a handful of consumer complaints
each month that a dealership or service provider has blamed
a vehicle sensor repair on our product. We take each complaint
very seriously and see it as an opportunity to stop a consumer
from being taken advantage of. We investigate the situation
thoroughly and take full responsibility for resolving the
issue. For more information on how we educate and persuade
the service provider to reconsider their position, see Mass
Air Flow Sensor Information & Testing. We are so confident
in our ability to resolve these situations and to help a consumer
fight back that we offer our Consumer Protection Pledge. As
a result of our standing up for consumer rights and providing
assistance to resolve a disagreement, we have had over 300
actual sensors sent to us by dealerships who claimed our product
had caused them to fail. Microscopic, electronic and chemical
testing revealed that none of the sensors were contaminated
by K&N oil (K&N Detailed MAF Sensor Test Results).
What is perhaps the single biggest clue to what is going on
is that over 50% of these sensors were not broken in the first
place for any reason. Click here for more information on how
this may happen.
A K&N Product Cause My Check Engine Light Or Service Light
To Come On?
installed K&N product should not cause the Service Light
to illuminate. For more information see our Engine Service
Lights and K&N Products page.