The maintenance interval has changed over the years on several items, however, the valve lash adjustment remains the same at 150,000 miles (240,000 km) and the fuel filter replacement remains at 15,000 miles (24,000 km). The oil change interval is 7,500 miles (12,000 km) and is duty cycle based. This interval will vary because the mileage will fluctuate based upon how the driver utilizes the vehicle. This engine uses an oil change monitoring system which will display a message on the vehicle information center that alerts the driver to change the oil.
Don't forget that your new Cummins 6.7L Turbo Diesel engine requires low-ash engine oil; failure to use this type of oil can result in serious damage to the exhaust aftertreatment system in your vehicle. Be sure to purchase engine oil that meets CES 20081 standards and has a maximum 1.00 mass % content of sulfated ash.
Due to the new EPA regulations, owners of MY07 and later Cummins 6.7L turbo diesel-powered highway vehicles must refuel only with Ultra-Low Sulfur Diesel (ULSD) fuel meeting a 15-ppm on-highway requirement. Use of all other fuels is prohibited and may result in damage to the engine and/or the aftertreatment system. Be sure to purchase your diesel fuel from a reputable fuel station. For most year-round service, a high-quality No. 2 diesel fuel that meets ASTM specification D-975 (0.0015% sulfur level) will maintain good performance. EPA requires retail fuel stations that carry and dispense LSD and ULSD to label the pumps with a Low-Sulfur Highway Diesel Fuel and an Ultra-Low Sulfur Diesel label.
In addition, diesel fuel sold for off-highway use should not be used in any Cummins turbo diesel engine. This is due to off-highway fuels not necessarily meeting the fuel cleanliness or lubricity requirements for on-highway fuel specifications. Use of such off-highway fuels can result in accelerated wear to fuel system components.
Keep in mind that your 6.7 liter engine is a sophisticated, fully integrated system. Some aftermarket products can jeopardize this system and cause severe power system, exhaust system and engine damage. For instance, there are a number of products that claim to enhance engine performance. These so-called aftermarket, "performance chips" may carry claims to increase horsepower, torque output, and/or fuel economy. These non-original chips can alter how the engine operates and their claims are neither authorized nor recommended by Dodge or Cummins. Keep in mind that your truck’s electronic control system can detect and store information about any modifications that increase horsepower, torque, and/or fuel economy. This information is stored in the system’s memory and cannot be erased – even if the modification is removed. Use of these unauthorized products can affect your warranty coverage.
For complete maintenance information, please consult your Owner's Manual or Operations and Maintenance Manual.