K&N is all about better flow. Better flow is not always better. Better flow is only optimal for pure racing conditions and is not necessary for a contour. The whole idea of the k&n air filter is ridiculous. It is an excellent race filter, but terrible for everyday use. Just think how could a simple drop in (filter) and 5hp. More air is getting in... but so is more dirt. Thats why many people have dirty mass air flow problems that set engine lights. You realy have to clean the filter almost on daily basis (depends on conditions). My guess the same applies for an oil filter unless proven otherwise. I go with fl-820s
