the K&N are great on real cars, but not so good on RC's. The foam type like the motor saver filters work a lot better for getting the fine particles. The K&N might do ok on-road, but I know they're not good off-road so I would ask someone that does a lot of on-road stuff. You can check out towerhobbies or ebay to find the motor saver, I would think you could find one on ebay for around 10 bucks. Do you have air filter oil? I keep some extra filter elements clean and oiled, then when I'm out running my car I can just switch out and put a clean one in in about 1 minute instead of having to take it out, wash it, dry it, and oil it before I can run again.