The 2018 Ram 2500 6.7 oil capacity and type are critical details for maintaining the longevity and optimal performance of your heavy-duty pickup. Owners of this robust truck, powered by the legendary Cummins 6.7L inline-six turbo diesel engine, understand that proper maintenance is paramount. Using the correct oil and ensuring the right fill level directly impacts everything from fuel efficiency to emissions compliance and, most importantly, the engine’s lifespan. Disregarding these specifications can lead to costly repairs and reduced reliability, making it essential for every owner to be well-informed.
Understanding the Legendary 6.7L Cummins Diesel Engine
The Cummins 6.7L turbo diesel engine is renowned for its durability, power, and towing capabilities, making it a popular choice for those who demand serious performance from their trucks. Found in the 2018 Ram 2500 and 3500 series, this engine is a workhorse designed to handle tough jobs, heavy loads, and countless miles. Its sophisticated design includes advanced emissions systems, such as Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR), which place specific demands on the engine oil. To protect these sensitive components and ensure the engine operates as intended, the choice of lubricant is not just a recommendation—it’s a requirement.
2018 Ram 2500 6.7 Oil Capacity: Getting the Fill Level Right
For the 2018 Ram 2500 with the 6.7L Cummins diesel engine, the standard oil capacity is approximately 12 quarts (or 3 gallons). This is a substantial amount compared to most gasoline engines, reflecting the diesel engine’s larger size, higher operating pressures, and the need for enhanced cooling and lubrication.
It’s crucial to measure accurately when adding oil. While 12 quarts is the general guideline, always consult your owner’s manual for the precise specification and use the dipstick as your ultimate guide. After filling, run the engine for a few minutes to circulate the new oil, then shut it off and wait about 5-10 minutes for the oil to settle before checking the dipstick. The oil level should be between the “MIN” and “MAX” marks.
Why is precise measurement so important?
Underfilling: Running with insufficient oil can lead to inadequate lubrication, increased friction, overheating, and accelerated wear on critical engine components like bearings, pistons, and the turbocharger. This can result in severe engine damage.
Overfilling: While seemingly less harmful, overfilling can also cause problems. Excess oil can be whipped into a froth by the crankshaft, leading to aeration. Aerated oil doesn’t lubricate as effectively, reducing its ability to protect components. It can also increase crankcase pressure, potentially leading to seal leaks, and can even foul emission control systems or injectors.
Recommended Oil Type for Your 2018 Ram 2500 6.7
Selecting the correct oil type is arguably even more critical than getting the capacity right. The 6.7L Cummins engine requires a specific type of diesel engine oil to function properly and protect its advanced systems.
The primary specification you’ll need to look for is API CK-4 or API CJ-4. These designations indicate that the oil is formulated for modern high-speed four-stroke diesel engines designed to meet 2017 and later model year on-highway and Tier 4 non-road exhaust emission standards. More importantly for the 2018 model, these oils are specifically engineered to be compatible with exhaust after-treatment systems, such as Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR), minimizing ash buildup that can clog DPFs. While CJ-4 was the standard for a while, CK-4 is the newer, more robust standard, offering improved oxidation stability, shear stability, and aeration control.
Regarding viscosity, the most commonly recommended grades for the 2018 Ram 2500 6.7L Cummins are:
15W-40: This is the most common and widely recommended viscosity for general use and warmer climates. It provides robust protection in a wide range of operating conditions.
5W-40: This synthetic or synthetic-blend option is often recommended for colder climates, allowing for easier cold starts and better oil flow at low temperatures. Many owners also prefer 5W-40 for its enhanced performance and potentially longer drain intervals, even in moderate climates.
Always check your owner’s manual for the exact recommended viscosity based on your climate and expected operating conditions. Reputable brands that meet these specifications include Shell Rotella T6 (5W-40) or T4 (15W-40), Mobil Delvac, Valvoline Premium Blue, and Mopar-branded oils.
The Importance of Regular Oil Changes
Even with the correct oil type and capacity, regular oil changes are the cornerstone of diesel engine maintenance. Diesel engines inherently produce more soot during combustion, which contaminates the oil, reducing its lubricating properties and increasing wear. Over time, engine oil breaks down due to heat and oxidation, losing its ability to protect vital components.
Key benefits of regular oil changes:
Reduced Engine Wear: Fresh oil with its full additive package provides optimal lubrication, minimizing friction and wear on moving parts.
Improved Fuel Economy: Clean oil allows the engine to run more efficiently, potentially leading to better fuel mileage.
Optimal Emissions Performance: Fresh oil helps prevent soot buildup and protects the emissions control systems.
Extended Engine Life: Ultimately, consistent oil changes are the most effective way to ensure your Cummins engine reaches its maximum potential lifespan.
The manufacturer’s recommended oil change interval for the 2018 Ram 2500 6.7L Cummins typically falls between 7,500 and 15,000 miles, or every 6 to 12 months, depending on usage. If you regularly tow heavy loads, operate in dusty conditions, or idle your truck frequently (severe duty), you might need to change your oil more often. Always replace the oil filter simultaneously with the oil, as a clogged filter can compromise the new oil’s effectiveness.
DIY Oil Change Tips and Considerations
For the mechanically inclined, performing an oil change on a 2018 Ram 2500 6.7L Cummins is a manageable task. You’ll need:
1. 12 quarts of API CK-4/CJ-4 diesel engine oil (e.g., 5W-40 or 15W-40).
2. A new oil filter (e.g., Mopar, Baldwin, Fleetguard).
3. A large drain pan (capable of holding at least 12-15 quarts).
4. A wrench for the drain plug and an oil filter wrench.
5. Gloves and rags.
Steps:
Warm up the engine slightly to help the oil flow better.
Safely raise and support the front of the truck if needed for better access to the drain plug and filter.
Place the drain pan beneath the drain plug and remove the plug.
Allow all the old oil to drain completely.
Remove the old oil filter. Be prepared for additional oil spillage.
Apply a thin film of new oil to the gasket of the new filter before screwing it on hand-tight.
Replace the drain plug securely.
Refill the engine with the recommended amount of new oil (start with 11-11.5 quarts).
Start the engine, let it run for a few minutes, then shut it off.
Wait 5-10 minutes, then check the oil level with the dipstick, adding more if necessary until it’s between the “MIN” and “MAX” marks.
* Properly dispose of the old oil and filter at a certified recycling center.
Conclusion
Maintaining your 2018 Ram 2500 with the 6.7L Cummins diesel engine requires diligence and adherence to manufacturer specifications. Knowing the correct 2018 Ram 2500 6.7 oil capacity and type—12 quarts of API CK-4 or CJ-4 oil, typically 15W-40 or 5W-40—is not merely technical information; it’s essential knowledge for ensuring peak performance, protecting your investment, and avoiding costly engine damage. Regular oil changes with the right products will keep your powerful Cummins engine running strong for many miles to come, ready for whatever challenges you throw its way.
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Source:
Ram 2500 Owner’s Manual (2018 Model Year) and Cummins Engine Specifications.