Originally Posted by coogs08
I just installed a K&N filter last night. Don't notice much except it is a little louder at higher revs.
Your 2009 MY is in the category that will get the most benefits from changing the filter (by getting rid of that charcoal liner). However, 2-5hp is not something you will obviously notice from the seat of the pants. But all the small improvements combined together do eventually add up.