Owned this dependable 5.9l cummins for 10 years never a problem. Last year no def. 19 mpg & 14 mpg towing 13000 lb fifth wheel. Air bags, air ride rancho 9000 system with on board air compressor, smarty j tuner, cold air intake, 5th wheel setup. New MBRP PERFORMANE Exhaust, new brakes & rotors, Cruise, new ac, ice cold.