This worked great on my 2009 f150. I bought the 50 series because I was told it had a nice deep tone with no cockpit rumble. I first installed it and turned it down in front of the axle, it was loud and had a great sound, but it was too loud for me in the cockpit. I went back and put the twist down on the axis with the bend from the original tube. It changed the world! I still have the same pleasant noise outside but no rumble inside. In fact, I only hear it when I step on it, which is nice. I definitely recommend it.