I'm almost certain U.S. models produced in 2013 & 2014 had the chrome quieter exhaust. In 2015 & 2016 the exhaust was black and a deeper tone. I've owned both and prefer the black over the chrome. Also, I put a set of black OEM exhaust on a red 2013 F6B and it looked so much better than the chrome. Personally, I can't tell much of a difference in the exhaust note out on the road.