Air filter test

Gday
Well that was a two sandwich and a cuppa tea read.
Very interesting.............
Murray

Hi Stu

That test has been around for 4 years now and I did consider it
at the time but careful examination revealed the flaws as applied
to australian conditions and I personnaly stick with oiled ones
which I can service whilst on a trip if needed.
I have always avoided the K&N type except for track work.

With air filters there are basic mistakes that can be made.

One is that maximum air flow is good/needed/required

The reality is that maximum air flow is only required when
engine is trying to deliver max power, which is very rarely the case
and the difference between filters of say 92 to 96 % is almost irrelevant. If air flow is changed then a car needs to be checked for correct mixture else damage may occur, this is particularly important for those cars that have fixed injection pulse widths when running open loop engine management systems like my Patrol (petrol).

Another important point is the size of the dust particles.
If you research the subject a bit you can find that results change
a lot with different dust size distributions.

Much of our bulldust here is below 4 microns in diameter which is
smaller than the holes in most paper filters, and hence the use of
a paper filter is a guarantee of dust into your engine.

The oiled ones work by changing the direction of air flow and
centrifugal force causes the particles to go straight ahead
and stick to the oiled foam and hence they work with all particles.

The biggest real case against oiled foam comes from improper
fitting and over oiling and for this reason only many are better off with paper filters, provided they do not fit a new filter just before
going bush whilst its pores are still wide open and pass fine dirt easily.

Gotta ask why all earthmoving equipment that work in horrendous amounts of dust and get huge hours out of their engines use paper filters.

Another interesting bit on airfilters at lcool.

I used the oiled filters for about 10 years, and they are a PITA to service. I run with the washable paper Toyota ones these days. I'll go with the theory that a small amount of very fine dust does no damage.

I wish I could find a "cleanable" air filter for the T/D Jack... you have to be very careful with the oiled foam iones as microscopic oil particles contaminate a sensor and this causes the "check engine" light to come on & sometinmes shutr the engine down and then you have to replace ($227) or clean in Metho $1.75....
The paper filters for the Jack non genuine cost $76 ea and I run two, one I clean in my large ultrasonic cleaner in metho & detergent and spin it to dry while the other is in the car....
The days when you had an Oil Bath air filter have gone, remember those, the oil bath underneath some coarse steel wool and the sucking action drew the oil up into the steel wool and filered out the dust...

Here's a site that I found which I thought was pretty good.Site Link