Selecting the correct 2018 Ram 2500 oil type is fundamental to preserving the longevity and capability of one of the most robust trucks in the full-size segment. While the procedure of changing oil might appear straightforward, the specific requirements for a heavy-duty diesel application diverge significantly from a standard gasoline vehicle. Utilizing the incorrect viscosity or failing to meet the manufacturer's specifications can lead to decreased fuel efficiency, increased wear, and potentially severe engine damage over time.
Understanding the 6.7-Liter Cummins Diesel
The heart of the 2018 Ram 2500 is the 6.7-liter inline-six Cummins diesel engine, a unit renowned for its durability and towing prowess. Unlike the gasoline variants, this diesel powerplant operates under extreme pressures and temperatures, demanding lubrication that can withstand significant stress. The oil in this system serves multiple critical roles, including lubricating moving parts, cooling the combustion cycle, and keeping the unit clean by suspending contaminants.
Recommended Viscosity and Specifications
For the majority of drivers operating the 2018 Ram 2500 with the 6.7L Cummins, the optimal 2018 Ram 2500 oil type is 5W-40 viscosity. This specific grade provides the necessary protection during cold starts, allowing the oil to flow quickly through the engine components, while also maintaining a stable, thick consistency at high operating temperatures. It is imperative to look for oil that meets the Cummins-specific specification of CES 20071, which ensures the additive package is compatible with the diesel particulate filter (DPF) and after-treatment system found on this model year.
Synthetic vs. Conventional Blends
While conventional mineral oil was standard in decades past, modern engineering strongly favors a full synthetic blend for diesel engines. Synthetic 5W-40 oil offers superior thermal stability, meaning it resists breaking down under the intense heat generated by the Cummins engine. It also provides better cold-flow properties and enhanced detergency, which helps keep the intricate passages clean, especially important for trucks used for towing or hauling heavy loads in varying conditions.
Capacity and Change Intervals
Maintaining the 2018 Ram 2500 requires attention to volume and schedule. The oil capacity for the 6.7L Cummins engine is approximately 15 quarts, though this can vary slightly depending on the specific configuration. While the truck is capable of extended intervals, adhering to the severe-service schedule is recommended for peak performance. This typically means an oil change every 7,500 to 10,000 miles, or six months, whichever comes first, to ensure the soot and acids generated by the diesel combustion process are effectively managed.
Compatibility with After-Treatment Systems
Modern diesel engines are tightly integrated with complex emission control systems. The 2018 Ram 2500 utilizes a diesel particulate filter (DPF) and selective catalytic reduction (SCR) system. Using the correct 2018 Ram 2500 oil type is vital because improper oil can contribute to ash buildup in the DPF, leading to clogging and expensive repairs. The CES 20071 specification is specifically designed to minimize these issues, ensuring the lubricant complements the emissions hardware rather than working against it.
Seasonal Considerations and Severe Use
Drivers in regions with harsh winters will appreciate the 5W rating, as it ensures the oil remains fluid enough to protect the engine during cold starts. For those who use their Ram 2500 for towing, off-roading, or constant hauling, the protection offered by the correct synthetic 5W-40 is non-negotiable. These severe conditions cause the engine to work harder and generate more heat, making the stability of the oil viscosity a critical factor in preventing premature wear.
