Last year I am coming back from Grayling MI heading back to Indiana. I had my Cummins Turbo cruise set on about 68, here comes this gasser chevy pickup pulling his trailer down a hill running about 80. He passes me with his dual pipes. I never touched my cruise, and a big hill was coming up, I caught up and passed him in the right lane. When he got next to me he stomped it down and tried to out pull me up the hill. I just kept going and kept the cruise on. Just watched my boost go up a little and up the hill I went. Love my Cummins turbo diesel.