If you get a 6.7L diesel of that vintage with 120K or more on the odometer plan on replacing the High Pressure fuel pump asap. The Bosh CP4 used diesel fuel to lubricate and cool itself. If was designed to use European Diesel which has a higher level of lubricity agent in it. The US ULSD causes excessive wear, When the pump fails it sends metal shavings to the injectors and trashes the engine. Thats a $16,000 repair. It happened to two of my friends. I spent $2400 to get mine replaced at 122,000 before it grenaded and took out my motor
Do a google search on the Bosch CP4 fuel pump.
