I drove a semi-truck from Seattle, WA to Roseburg, OR once. That dang thing had to be pulled over around every 35 minutes due to loss of power during the regen. Being as it was a day cab, the stack come up behind the passenger seat behind the cab. I thought the cab of the truck was going to melt, because I could feel the heat inside the cab. That was a long (last time I drove that truck) and painful trip.