Recently had my '08 F350 checked for possible DPF problems and reduced MPGs. Ford said the DPF was OK but did re-flash the computer with what I was told would improve the MPG. The update also had a sheet of instructions on the " new regen messages" I would be receiving...kind of disconcerting in that once the regen starts I must continue driving for at least 30 minutes at a speed faster than 30MPH. If I don't follow the instructions the DPF warranty will be useless due to owner error. Seems that a person can't be expected to drive an unscheduled distance for 30 minutes so that the engine will work properly. Am I missing something here? What change did they program into my truck that would improve the function?