DeTomaso Mailing List: September 2000, Message #203

I have been beconed for an answer.  

Caterpillar uses a tripple filter.  The first stage is a turbin chamber
that swirls the air and takes out the biggest particles.  Then comes two
stages of paper filter.  One inside of another.  They have a differential
pressure sensor in the inlet tract to determine when to change the filters.  

Now Cat uses paper for one simple reason.  It is cheaper to change the
filter than it is to remove it, clean it, oil it, and reinstall.  It is all
about money.  Parts are often cheaper than labor.

Dave "breating easy" D

At 03:43 PM 9/6/00 -0400, you wrote:
>snip.....
><Independent studies on fleet vehicles have shown that the use of K&N
filters (specifically) to achieve cost benefits through increased
performance, mileage or other
>perceived gains, has been more than offset by added expense on the
maintenance end of their budgets.>
>
>Increased airflow with the same driving force into the same size inlet has
to mean less inlet restriction and maybe less actual grit-removal. K & N
are vigorous in their defense of their product, though, which seems to work
OK on my dirt bikes, as long as its cleaned & oiled regularly. That seems
to be key: K & N say not cleaning & reoiling enough (per directions) for
your local conditions constitutes "misuse of the product". IMHO, most
people won't even inspect the things regularly, much less wash & re-oil.
Dave Doddek, what does Caterpillar use on their earthmover engines, and
whats the freq. of engine repair?  Cheers- J Deryke
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