Been reading the operators Manuel but ?? When I got home yesterday and parked in garage I walked around behind it and it smelled a bit hot. Cold outside. I noticed the def gauge was down a bit this morning. Did I have a regen event. Doesn’t the truck tell you when it’s happening and how long does it take etc. Also I really like the tow haul mode. But does the exhaust brake come on by itself in th mode or not. I think not. But it’s hard to tell. Just firm down shifts I think. Now the gear limit. Plus or minus Where would that be useful? Coming down a windy steep road with a load on or behind and locking it into 2 nd or third to get full exhaust braking is my guess. Got to watch the rpms too I’m assuming it locks the torque converter ? My exhaust brake seems to go to about 12-13 mph before it goes off. Also when do you add def Like when the gauge says half full. Would that be a good time to top off. The service brakes are very nice on this truck. Driving on slick snow empty they stop you straight and steady. I’m inpressed. I have been slamming them on try to get it to go sideways and it won’t do it. Very stable truck all in all 3500 doesn’t ride has rough as my old 99 2500 with firestones and ranchos on it