My biggest disappointment in my new to me coach was how the Jake Brake worked. My last coach had a PacBrake and I felt it held me back better. My last coach had the PacBrake programmed for 4th gear. I live in the hills around Branson & most of the roads you're driving under 50 mph. My Jake Brake was progammed for 5th gear. I had my Jake Brake reprogrammed to 4th gear & what an improvement. I now love my Jake Brake!