M
I pulled the air filter with ~400 miles (700km) on it just to check, and it is dirty so i'll replace it, but had I of not pulled it I would have no problems running it to about 600 miles (1000km). ~60 bucks every 1000km is fine with me. Not ideal, but not the end of the world. The Polaris I had went through filters in about the same time frame. They were about 10 bucks cheaper, but not a big deal.