Everyone
has known about K&N's air filters for years. What is not as
well known is they also make an excellent oil filter. One of
the
most prominent features on the K&N filter is the large 25mm
nut on top of the filter. This provides a very easy means for
removal as well as a way to safety wire the filter to the chassis, as
required by some racing bodies. While this is leaps and bounds easier
than trying to get a strap wrench on a traditional filter and
safer than impaling a stuck filter to remove it, the nut has a slight
taper. This causes the socket to want to back off and free spin. So if
you are using the 25mm nut to remove the filter, make sure to
keep some downward pressure on the wrench as you turn it.
Everyone knows that it is what is on the inside that counts. Upon
opening the
K&N filter, you will see it has a fairly traditional lay out. A
filter element and a drain back valve are at the core of the unit, held
in place by a leaf spring. Also worth noting is the very thick case. I
do
not see any way this filter could fail, with the exception of possibly
the extreme pressure of drag racing.
When
tested for flow at 30psi with 10w40@ 90 degrees, the K&N unit
flowed 13% more oil than its Mann counterpart. Based on published
numbers this would be ~8% more than the Mobile 1 filter. It is worth
noting that the K&N filter is rated at 20 micron filtration,
not
the 10
that Mann is or the 15 for Mobile. Based on the driving habits and oil
change frequency of most Volvo drivers, I feel the slight decrease in
filtration is not a major concern and is out-weighed by the additional
flow.
The more surface area a filter has, the more contaminants it can trap
before becoming obstructed. The K&N Performance Gold oil filter
has a total of 150in^2 of filter media secured in place by epoxy,
leaving a total of ~135in^2 of usable filter surface area. This is on
par with other filters of its size.
As a
comparison above
is a Fram X2 oil filter cut open. You can see the leaf spring has a
coil spring to assist which is retained with a piece of
plastic. The
drain back valve was also hard plastic and had actually failed
in
this filter. The case is also much lighter and the filter element caps
are paper not steel.
I first installed a K&N oil filter in September of 2007.
From
what I have seen, I intend to continueto use them with no
intention of changing to
something else. Even at about $13 dollars, which is about the going
rate for a premium filter, this a great choice for peace of mind.
