I wonder if I should be using exhaust brake when I tow. I have a 2022 Mega cab 2500 Diesel that gets about 12 mpg towing my 11,000 lb. trailer. It's pretty flat around here and mostly interstate miles. I don't know anything about exhaust braking, other than the one time I tried it I was driving down the interstate and it went into limp mode. I had to pull it over and shut it off, but it ran just fine when I turned it back on without exhaust brake so I've been afraid to use it.