Not sure which 2013 Ford Focus Air Intake Systems are right for you? We have over 627 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Shawn K from SAINT AUGUSTINE, FL said, "This K&N did give me more HP but I am not sure about the MPG. I put this on my brand new car and didnt think twice about the purchase. All in all I would buy this again."