Bill,
I don't think much passes through the K&N, or they would have been out
of business years ago.
They wouldn't have even been on the map.
However, seeing as you are so sceptical, I have the solution to your
feared abrasive ingestion problem.
Mount a Mack Truck air filter on the roof of your Van---Pooof!!------ no
more fear of your little 4 banger eating a little dust!:>)
Problem solved--
Case closed.

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Terry 85 GL