Join Date: Jun 2008
Location: Southeast Michigun
Yes, 25k is not unheard of... There's just no need for it sooner than that. Heck, they actually filter out MORE particulate the more clogged they get. Yes, they begin losing efficiency at some point, but it takes a LOT to get it to that point.
Heck, the Ford Focus circa 2005 or so comes with a 'lifetime' air filter. It can hold up to (IIRC) 500 grams of particulate before its performance affects engine operation. Most paper filters accumulate less than 10% of that over the life of the vehicle combined.
IMHO, check it at 25k and see if it's looking grungy, but there's honestly no need to clean it any sooner than that. In all reality, it can probably go MUCH longer.
I also forgot to mention in my earlier post that my 4.0L Ford engine displaces four times the air that a VStrom does, and its filter is roughly 2/3 the size of the Strom's filter. Don't worry about it... Inspect it? Sure. But I wouldn't bother touching it unless it's really bad...