The K&N filter is a poor filter it lets alot of the fine dirt get through. I have found the best filter to be a Amsoil filter. They have two choices one with a sticky oil you can spray on it or the new Ea filter which is a synthetic fiber filter that uses no oil and flows close to what a K&n does ,but traps almost every particle of dirt. I give TDR customers a 10% discount on Amsoil products.