2020 Ram 2500 Fluid Specs & Capacities

Quick Reference: 2020 Ram 2500 Fluid Specs

Engine Oil

For the 2020 model year, Ram equipped the 2500 with two distinct powerplants, each with its own specific engine oil requirements.

• 6.4L HEMI V8: This gasoline engine demands a high-quality 0W-40 synthetic oil that meets API Service Category SN and FCA Material Standard MS-12633. Using a full synthetic oil is critical for meeting the performance and longevity standards of this modern engine. The crankcase capacity is 7.0 quarts (6.6L).

• 6.7L Cummins Turbodiesel: The legendary Cummins engine requires a robust diesel-specific oil. The preferred viscosity is 10W-30 for most operating temperatures, but 5W-40 synthetic is recommended for cold climates or severe-duty use. Regardless of viscosity, the oil must meet API Service Category CK-4 and Cummins Engineering Standard CES 20086. Never use a gasoline engine oil in the Cummins. Oil capacity is 12.0 quarts (11.4L) with a filter change.

Engine Coolant

The entire 2020 Ram HD lineup uses a specific Organic Acid Technology (OAT) coolant. It must conform to FCA Material Standard MS-12106. The Mopar-branded coolant is purple. It is critical not to mix this with other coolant types, especially the older orange or pink/red Hybrid Organic Acid Technology (HOAT) coolants used in previous model years. Mixing OAT and HOAT can cause the coolant to gel, leading to blockages, overheating, and catastrophic engine damage. Always top off and flush with the specified OAT coolant. System capacity varies significantly based on engine and options, ranging from 16.5 to 24.3 quarts.

Transmission Fluid

Transmission fluid is not a one-size-fits-all product. Using the incorrect fluid can destroy a modern automatic transmission in short order.

• 8HP75 8-Speed Automatic (paired with 6.4L HEMI): This transmission requires Mopar ZF 8&9 Speed ATF, which meets FCA Material Standard MS-90030-A2. This is a highly specific, low-viscosity fluid. Do not use ATF+4 or any other type of "universal" ATF.

• 68RFE 6-Speed Automatic (paired with 6.7L Cummins): This heavy-duty transmission uses Mopar ATF+4, a workhorse fluid specified under FCA Material Standard MS-9602. While many brands license and produce ATF+4, ensure the bottle explicitly states it is licensed to meet this spec. An initial drain and fill (pan drop) requires approximately 6.5 to 7.0 quarts.

Drivetrain Fluids (Transfer Case & Differentials)

For 4WD models, the transfer case and differentials require specific gear lubricants.

• Transfer Case: The BorgWarner transfer cases (BW 44-46, 44-47, etc.) used in the 2020 Ram 2500 require a dedicated Mopar BW44-46/47/48/49 Transfer Case Fluid. Do not substitute ATF or generic gear oil. Capacity is 1.6 quarts (1.5L).

• Front Differential (AAM 9.25"): The front axle requires a high-quality 75W-90 Synthetic Gear Lubricant. Capacity is approximately 2.3 quarts (2.2L).

• Rear Differential (AAM 11.5" / 12.0"): The rear axle also calls for 75W-90 Synthetic Gear Lubricant. If the truck is equipped with a limited-slip differential (LSD), ensure the gear oil you use already contains the necessary friction modifier or add it separately as per the manufacturer's instructions. Failure to do so can cause chatter and premature clutch wear in the LSD unit. Capacity ranges from 4.4 to 5.3 quarts depending on the specific axle configuration.

Brake & Steering Fluids

• Brake Fluid: The hydraulic brake system requires a fluid that meets DOT 3 specifications. DOT 4 fluid can also be used as it has a higher boiling point and is compatible, but DOT 3 is the factory minimum. Never use DOT 5 silicone-based fluid, as it is incompatible with the system's seals. The system should be flushed every 2-3 years, as brake fluid is hygroscopic and absorbs moisture, reducing its effectiveness and corroding internal components.

• Power Steering Fluid: The 2020 Ram 2500 is equipped with Electric Power Steering (EPS). This system does not use any hydraulic fluid, so there is no reservoir to check or fluid to change.

Other Fluids

• Diesel Exhaust Fluid (DEF) (6.7L Cummins Only): All modern Cummins engines require DEF to meet emissions standards. Use only high-quality DEF that is API Certified and meets ISO 22241. Using contaminated or poor-quality DEF can damage the expensive Selective Catalytic Reduction (SCR) system. The DEF tank holds 5.0 gallons and is easily filled via the blue-capped filler neck next to the diesel fuel filler.

• Windshield Washer Fluid: Use any quality commercial windshield washer solvent. For winter use, select a fluid with an appropriate freeze-point rating.

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