Due to winter here in Canada, I drive my car for about 6 months of the year; often only once a week. I have a K&N drop in and I am wondering when to re-oil. It is only about a year old and not dirty at all. How can you tell when to re-oil it? I have heard that too much oil is not good as it clogs the maf, but at the same time I do not want to be sucking dirt and what not into the engine. Thanks for the help