K&N filters are...

[SteveD]

Yes, it does matter, but me thinks since you're a gearhead like the rest of us.....oil changes were done religiously and you cleaned the K&N more often than not. That pretty much takes care of the air filter debate, unless, of course you use an SM58 pop filter (windsock) instead...YMMV

But that's the thing about the K&N. If you only clean them every 50K they will filter better...apparently.

[ME 109]

I've run K+N for a while with a clean enough airbox.
Next time yer pull yer K+N out, hold it up to the sunlight and see what's there. Pinholes of light!

I washed mine gently (not very often) and oiled it appropriately. Pinholes of light!

That means a hole.