Not a Dynamax but an earlier front engine diesel Super C. I have 50K+ on an ’06 C5500 in a Seneca 34SS. Most of the miles have been in the west up and down the Sierras and Rockies with the foot on the floor on the ups. Replaced one glow plug last October and that is it for the motor and trans. beyond the fluid and filter replacements. Love the turbo going up and the exhaust brake on the way down. The tank holds 80 gallons of diesel and I spend them frivolously towing a PT Cruiser on a dolly at 62+ in CA and faster in other states averaging 8.5gph for all trips. If I had my druthers I would like another 50-100 more horsepower just for fun and another 40 gallons of fuel as I don’t care much about mpg but would like more mpt (Miles per tank). It is about as complicated as an anvil and should outlast me. I get the motor, she gets the home and we are both happy. Enjoy the ride.