[Christ]

So here's what you do:

Buy a new OE filter, Wash your K&N and re-oil per mfg directions.

Fill the tank, noting vehicle position, fill rate, pump and station.

Install paper filter, drive 50 miles of highway, fill up and do it again.

Go back to the K&N and do the same, filling up from the same station/pump every time, to keep variables to a minimum.

Go back and do the paper filter one more time, two more runs.

Average the first two, the second two, and the third two, and figure the difference.

It's not exactly scientific, but it's the closest test you're going to get that doesn't take a year to complete.

If you show enough of a mileage gain to be attributed to the filter and not just some random circumstance, I'll drop the subject.