Senior VR Member
Join Date: Jun 2017
Thanked 58 Times in 56 Posts
Not wanting to start any controversy and certainly respect the experts here (as they have far more motor knowledge than I do)
I just want to state 2 facts that are first hand to me.
Our bikes ( 2008 C50 and wife's 2006 C50) both before and after installing after market air filters, have always gotten 60+ MPG.
My bike-- stock pipes with holes drilled into the baffles, has the Bike master air filter. Sherri's bike-- Cobra Street Rod pipes, has the K&N air filter. 1) the miles per gallon did not change 1 iota when we switched to the after market air filters. 2) they feel like they have a tiny bit more power- but I'm willing to say that's just in my mind. But neither run worse or needed any kind of adjustment.
Of these two facts I am positive.
Why did we switch to the filters we chose. Pure economics. They were significantly lower in cost and easy to clean and replace as opposed to buying the stock replacement each time.
Just wanted give the original poster the other side of the coin.