2015 Ram 2500 Fluid Type Specs

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil (Gas/6.4L)	SAE 5W-20, API SN Plus or later, Mopar MS-6395	7.0 quarts (6.6 liters)
Engine Oil (Diesel/6.7L)	SAE 15W-40 (above 0°F), SAE 5W-40 (below 0°F), API CJ-4 or later, ACEA E9/E7, Cummins CES 20081/20086	12.0 quarts (11.3 liters)
Engine Coolant	Mopar/FCA OAT (Organic Additive Technology) conforming to MS-90032 (Purple/Pink)	~17-19 quarts (16.1-18.0 liters)
Transmission Fluid (66RFE/68RFE)	Mopar ATF+4 (MS-9602)	66RFE: ~11.5-12.0 quarts; 68RFE: ~17.0 quarts
Transfer Case (BW 44-46/44-47)	Mopar ATF+4 (MS-9602)	BW 44-46: ~1.6 quarts; BW 44-47: ~1.75 quarts
Front Differential	SAE 75W-90, API GL-5	~2.3-2.5 quarts (verify in owner's manual)
Rear Differential	SAE 75W-90, API GL-5 (without Heavy Duty Payload/Towing Package); SAE 75W-140, API GL-5 (with Heavy Duty Payload/Towing Package)	~3.0-4.0 quarts (verify in owner's manual)
Brake Fluid	DOT 3 or DOT 4	As needed
Power Steering Fluid	Mopar MS-9602 (ATF+4) or MS-5931	As needed
Washer Fluid	Mopar Windshield Washer Concentrate or equivalent	~1 gallon (3.8 liters)
Diesel Exhaust Fluid (DEF)	ISO 22241-1 / API DEF certified	5.0 gallons (18.9 liters) (Diesel models only)

Engine Oil

For 2015 Ram 2500 models, the engine oil specifications vary significantly based on whether you have the 6.4L HEMI gasoline engine or the 6.7L Cummins Turbo Diesel engine. Using the correct oil is crucial for engine longevity and performance.

6.4L HEMI Gasoline Engine

The 6.4L HEMI requires SAE 5W-20 engine oil. It must meet API SN Plus or later specifications and adhere to Chrysler material standard MS-6395. The capacity is approximately 7.0 quarts (6.6 liters) with a filter change.

Intervals and Pitfalls: Engine oil and filter changes are typically recommended every 10,000 miles or 12 months, or sooner under severe driving conditions (towing, extreme temperatures, prolonged idling). Always use a high-quality oil filter that meets OEM specifications. Using an incorrect oil weight or a non-MS-6395 compliant oil can lead to premature wear, reduced fuel economy, and potential issues with the Multi-Displacement System (MDS) on these engines.

6.7L Cummins Turbo Diesel Engine

For the 6.7L Cummins diesel, the oil specification is more complex due to temperature considerations. Above 0°F (-18°C), SAE 15W-40 is the recommended viscosity. Below 0°F (-18°C), SAE 5W-40 is recommended for better cold-starting performance. The oil must meet API CJ-4 or later specifications (such as CK-4), ACEA E9/E7, and Cummins Engineering Standard (CES) 20081 or 20086. The oil capacity is a generous 12.0 quarts (11.3 liters) with a filter.

Intervals and Pitfalls: Diesel engine oil change intervals can vary significantly based on driving conditions, oil analysis, and whether the truck is equipped with a modern exhaust aftertreatment system (DPF). Refer to your owner's manual for specific recommendations, but typical intervals can range from 7,500 to 15,000 miles. Always use oils specifically formulated for diesel engines and ensure they meet the listed Cummins and API specifications. Using gasoline engine oil or incorrect viscosity can lead to severe engine damage, especially to turbochargers and emission control systems.

Engine Coolant

Your 2015 Ram 2500 uses a Mopar/FCA OAT (Organic Additive Technology) coolant that is typically Purple or Pink in color. It must conform to Chrysler material standard MS-90032. The total system capacity is approximately 17-19 quarts (16.1-18.0 liters), depending on engine and cooling system configuration.

Intervals and Pitfalls: OAT coolant is designed for extended service intervals, often around 10 years or 150,000 miles. However, it's good practice to inspect the coolant level and condition periodically. Crucially, never mix OAT coolant with other coolant types like HOAT (Hybrid Organic Additive Technology) or traditional Green IAT (Inorganic Acid Technology) coolants. Mixing different coolant chemistries can cause chemical reactions that lead to gel formation, corrosion, and severe damage to the cooling system components, including the radiator, water pump, and heater core. Always use distilled water when mixing concentrate, though pre-mixed 50/50 solutions are convenient and recommended.

Transmission Fluid

The 2015 Ram 2500 can be equipped with either the 66RFE or 68RFE automatic transmission. Both transmissions require Mopar ATF+4 Automatic Transmission Fluid, which meets Chrysler material standard MS-9602.

• 66RFE Capacity: Approximately 11.5-12.0 quarts for a complete refill (dry) or pan drop and filter change.
• 68RFE Capacity: Approximately 17.0 quarts for a complete refill (dry) or pan drop and filter change.

Intervals and Pitfalls: Ram recommends transmission fluid and filter service under normal driving conditions at 120,000 miles. However, for vehicles used for heavy towing, hauling, or frequent off-road use, shorter intervals (e.g., 60,000 miles) are highly recommended. Only use Mopar ATF+4 or a licensed equivalent that explicitly states compliance with MS-9602. Never use generic "universal" ATFs or fluids not specifically rated for ATF+4, as they lack the precise friction modifiers and wear protection crucial for the longevity of these transmissions. Incorrect fluid can lead to harsh shifts, slippage, and premature transmission failure.

Transfer Case Fluid

For the BorgWarner (BW) 44-46 and 44-47 transfer cases found in the 2015 Ram 2500, the specified fluid is Mopar ATF+4 Automatic Transmission Fluid, conforming to Chrysler material standard MS-9602.

• BW 44-46 Capacity: Approximately 1.6 quarts.
• BW 44-47 Capacity: Approximately 1.75 quarts.

Intervals and Pitfalls: Transfer case fluid is generally recommended for inspection and replacement at regular intervals, often around 60,000 to 120,000 miles, or sooner if the vehicle is frequently used in 4WD, off-road, or for heavy towing. As with the automatic transmission, only use Mopar ATF+4 or an officially licensed equivalent. Using incorrect fluid can lead to accelerated wear of internal components and potential transfer case failure.

Differential Fluid

The 2015 Ram 2500 uses different differential fluid specifications based on the axle type and whether the truck is equipped with a Heavy Duty Payload/Towing Package.

Front Differential

Both the 9.25" and 10.5" AAM (American Axle & Manufacturing) front differentials require SAE 75W-90, API GL-5 gear oil. Capacity is typically around 2.3-2.5 quarts; verify this in your owner's manual or OEM service information based on your specific axle.

Rear Differential

The rear differential specification depends on your truck's configuration:

• Without Heavy Duty Payload/Towing Package: SAE 75W-90, API GL-5 gear oil.
• With Heavy Duty Payload/Towing Package: SAE 75W-140, API GL-5 gear oil.

For both rear differential types, capacities can range from 3.0 to 4.0 quarts. It is crucial to verify the exact capacity and weight in your owner's manual for your specific axle (e.g., AAM 11.5" or 12.0").

Limited Slip Differential Additive (if equipped): If your Ram 2500 is equipped with a limited-slip differential (LSD), you MUST use an appropriate limited-slip friction modifier additive, unless the gear oil explicitly states it is already friction-modified for LSD applications. Failure to use the additive can result in chatter, noise, and accelerated wear of the LSD clutches. Consult your owner's manual to determine if your truck has an LSD.

Intervals and Pitfalls: Differential fluid should be inspected regularly and changed according to the manufacturer's recommendations, typically every 30,000 to 60,000 miles, especially if towing or off-roading frequently. Using incorrect weight, non-GL-5 rated oil, or neglecting the LSD additive can lead to premature wear, noise, and differential failure.

Brake Fluid

The 2015 Ram 2500 requires DOT 3 or DOT 4 brake fluid. It is crucial to use a high-quality fluid from a reputable manufacturer. The system capacity is "as needed" for topping off, but a full flush will vary.

Intervals and Pitfalls: Brake fluid is hygroscopic, meaning it absorbs moisture from the air over time. This moisture lowers the fluid's boiling point, which can lead to brake fade under heavy braking, and also contributes to corrosion within the brake system components (calipers, master cylinder, ABS unit). It is generally recommended to flush and replace brake fluid every 2-3 years, regardless of mileage, or according to your owner's manual. Never mix DOT 3, DOT 4, or DOT 5.1 with DOT 5 (silicone-based) fluid. DOT 5 is incompatible with systems designed for glycol-based fluids and can cause severe damage. Always keep brake fluid containers sealed to prevent moisture absorption.

Power Steering Fluid

The power steering system in the 2015 Ram 2500 typically uses Mopar MS-9602 (ATF+4) or Mopar MS-5931 power steering fluid. Check your owner's manual specifically for the correct fluid type, as some models may specify MS-5931.

Intervals and Pitfalls: Power steering fluid does not have a strict replacement interval, but it's good practice to inspect the fluid level and condition periodically. If the fluid appears dark, burnt, or has a strong odor, it should be flushed and replaced. Using an incorrect fluid can lead to hard steering, pump whine, and premature failure of the power steering pump and rack and pinion/gearbox.

Washer Fluid

For the windshield washer system, use Mopar Windshield Washer Concentrate mixed with water, or a good quality, commercially available windshield washer fluid. Most washer fluid reservoirs hold approximately 1 gallon (3.8 liters).

Intervals and Pitfalls: Top off as needed. In freezing climates, always use a washer fluid rated for sub-zero temperatures to prevent freezing in the reservoir, lines, and nozzles, which can cause damage.

Diesel Exhaust Fluid (DEF)

For 2015 Ram 2500 models equipped with the 6.7L Cummins Turbo Diesel engine, Diesel Exhaust Fluid (DEF) is required for the Selective Catalytic Reduction (SCR) system. The DEF must meet the ISO 22241-1 standard and be API DEF certified.

The DEF tank capacity is approximately 5.0 gallons (18.9 liters).

Intervals and Pitfalls: DEF is consumed continually while the engine is running. The truck's onboard computer will provide warnings when the DEF level is low and will eventually de-rate engine power or prevent starting if the DEF tank becomes empty. Always use high-quality, fresh DEF from a sealed container. DEF has a shelf life and degrades over time, especially if exposed to direct sunlight or extreme temperatures. Store DEF in a cool, dark place. Never put diesel fuel in the DEF tank or DEF in the diesel fuel tank. This will cause severe and costly damage to the respective systems. If DEF freezes, allow it to thaw naturally; do not apply heat. The DEF system is designed to thaw itself during vehicle operation.

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