I think that Montana would weigh a lot more than the 12K dry weight. They may have a lemon but the great majority of people with diesels have few or no problems. In 110K on mine I've had one blown hose on the engine and a couple of minor electrical problems. I think that will be typical of most peoples experience. Pushing a gasser right to the limit of it's towing capacity, even in the flatlands, is asking for trouble. And the last time I was in Missouri it wasn't all that flat.
Maybe they should check on trading the lemon in on a newer diesel.
