​RE: K&N Filter in a WBX

When I first got my '90 Westy I picked up a K&N filter.  On my first long
trip I kept careful numbers on gas mileage.  at the midpoint of the trip,
at about 1,300 miles, I swapped in the K&N.  When I got home I compared
numbers, fresh stock air filter on the first half of the trip vs. the K&N.
And not a whit of difference that I could see.  I used the K&N for several
years but got lazy and went back to stock filters, don't have to clean and
oil them.  As Dennis said there have been various reports over time that
the K&N does not really do that good a job as an air filter.