So, aside from oil and filters, what are people doing for air filter
change intervals, do you follow the maintenance schedule in the owners
manual, or ????
Most of my vehicles have called for changes at around 15 or 20K miles
and that's more or less when I change the filter. Only exception is
if I are driving on dusty dirt roads behind people, then I might
change it after that kind of trip, just to be safe.
What about brands, do most of the denizens here revile Fram air
filters like they do their oil filters?
IMO, Fram makes an OK air filter, as compared with other brands.
My problem with them is that more and more of their products are being
made in China and Israel, especially their fuel filters. They layoff
the North American worker, but yet they want their former (currently
jobless) employees to buy their product. Excuse me, Honeywell. How
many of your top paid executives lost their jobs to a Chinese worker?
If you've been changing your filter between 15 & 20,000 miles and that
works out for you then there is no need to ask others about an interval
change. You also answered your own question about changing the filter
sooner if driving on dusty roads.
I change air filters between 30,000 & 40,000 My manufacturer (GM) says
Tried a Fram Fliter in the Bonneville once, was tight when I went to
remove it and ended up tearing off one whole side of the rubber gasket
that wrapped around it.
I use OEM filters from an Auto Parts store.
91 Bonneville 320,854
05 Park Avenue 93,589
On 15 Dec 2009 10:35:53 -0500, email@example.com (Scott Dorsey) wrote:
I read somewhere that banging them like that was a big no-no. It
would cause trapped dirt to become available on the wrong side of the
paper and would get sucked into the engine next time you started it. I
have no idea if that's true.
If they get clogged it might be evident, but if they don't filter very
well how would you ever know?
If it gets clogged, with modern cars it's very noticeable on acceleration
but it's often not noticeable at all at low speeds and at idle.
If it doesn't filter well, you'll notice it because when you clean
the throttle body and intake, it will feel gritty and not just gummy.
I have sadly experienced that feeling on cars using K&M filters....
"C'est un Nagra. C'est suisse, et tres, tres precis."
Back in the 1970s, I owned a 1962 Ford Falcon I had recently bought.One
time myself and a buddy were driving to Bloomington,Indiana, I wanted to
check out a Ford Model T a guy had advertised for sale in
Hemmings.Somewhere in Kentucky that night, my car quit running.We looked
under the hood, the air filter was completely clogged up.I removed the
air filter and my car started up and ran just fine.
I don't mind Fram air filters. Without test equipement you can't
really be sure about the quality of the media, but Fram's looks about
the same as other "national brands." Still, I see no reason to pay
more for Fram air filter if a Motorcraft air filter for my Fords are
on the same shelf for less.
One thing that is interesting to me is the idea that changing your air
filter too often is actually a bad thing.
"The SAE paper by Marty Barris (SAE Technical Paper No. 952557 titled:
'Total FiltrationTM: The Influence of Filter Selection on Engine Wear,
Emissions and Performance' ) offers two important conclusions:
a.. "The level of ambient dust concentration can easily overwhelm
other factors in terms of influence on engine wear. It is therefore
important to match the air intake filtration system design to the
anticipated ambient exposure. And here's an interesting one-:
b.. "Too frequent air filter change intervals can double engine wear
rate, especially if changed within the first 30% of the air filter's
"The practice of removing an air filter element to blow it clean is
plain stupid. This malpractice, which can lead to engine wear rates
being trebled, still occurs on the false economy basis of trying to
extend the service life of the air filter element. A well meaning but
badly trained technician thinks he is being thorough in servicing the
air filter, or replacing it prior to reaching the optimum life of the
element. This happens in workshops without supervisors even being
aware of it."
The following is from the "Nanofibers in Filtration Applications in
Transportation" listed link below:
"For most engine air filters, the function of the filter and the
corresponding engine wear are based largely on dust cake filtration.
The formation of a dust cake on the filter media changes many
important factors in the function of a filter media, including
filtration efficiency and pore size distribution. Engine wear rate has
been shown to be significant during the early portion of an air filter's
design life (Figure 9 in
"While vehicle manufacturers are specifying longer life air cleaners
and longer maintenance intervals, the actual service interval for air
filters varies widely depending on the sophistication of the vehicle
end-user and the maintenance staff. The most sophisticated end-users
are large fleet operators with several thousand vehicles. Air cleaner
maintenance is typically performed based on filter restriction using a
restriction indicator on the vehicle. Maintenance decisions are
largely made based on economic factors, and trained personnel provide
oversight on maintenance intervals and filter selection. The decisions
are based on a complex interaction of factors, including filter design
and efficiency, filter maintenance interval, filter and service cost,
and engine wear rate.
"Consumers must also make maintenance decisions about the air filters
in their cars. This user group is relatively unsophisticated in their
knowledge of filter maintenance and function. Air filters are perhaps
the most easily serviced but least understood parts on a vehicle.
Other common replacement parts on a vehicle such as tires, wiper
blades, oil and oil filters work best when new. However, this is not
the case with conventional air filters. Since most air filters rely on
the formation of a dust cake to improve the performance of a filter
media, over-servicing can lead to dire consequences from inadequate
"Air filter over-servicing is common for light vehicles. Light
vehicles are generally not equipped with filter restriction
indicators. Air filters are often inspected by maintenance personnel
during oil changes. In spite of the typical manufacturer's
recommendation of at least a 30,000-mile change interval, it is common
for dealers, service stations and quick lube businesses to recommend
more frequent air filter changes. Given the frequency of oil changes
and air filter replacements at quick lubes, it is expected many light
vehicle air filters are changed much more frequently than
"While this over-servicing phenomenon is frustrating to those who
understand filter media performance, the filter industry has not
sufficiently educated customers how air filters function. Not
surprisingly, filter manufacturers, distributors, dealers, service
stations, and quick lubes have economic incentives to change and sell
more air filters. It is also understandable that consumers believe air
filters work best when they are new (like other parts) and have a
Did you read the article? Donaldson is peddling their Nano-fiber
technology which they claim does not suffer from this limitation that
the filter needs to cake with dust before it starts working properly.
They claim their filter will work right straight out of the box. And
guess what? Other filter manufacturers also claim the same thing.
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