kohldad wrote:
The 5.9 has absolutely no engine braking until you add the exhaust brake. So the exhaust brake was the first mod I had done to the truck. The exhaust brake was so good, that despite hauling a 11,800# FW for over 40k miles including a trip out west and back, I still had over 50% pads at 140k miles. The 6.4 engine braking isn't much, but when they adjust the timing (or whatever), it makes a huge improvement. But still, I know I'll be lucky to get 100k out of the front pads.
X2
I knew that before we bought it and the dealer had it installed ready to go when we picked it up with 3 miles on it. Any 5.9 towing heavy should have one if you have grades to contend with.