2021 Ram 1500 Fluid Type Specifications – Repairius.com

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil (5.7L HEMI)	SAE 5W-20, API SP/SN Plus, Mopar MS-6395	7.0 quarts (6.6 liters)
Engine Oil (3.6L Pentastar)	SAE 5W-20, API SP/SN Plus, Mopar MS-6395	6.0 quarts (5.7 liters)
Engine Oil (3.0L EcoDiesel)	SAE 5W-40, API SN Plus/CJ-4/CK-4, ACEA C3, MS-10902/MS-12991	10.5 quarts (9.9 liters)
Engine Coolant	Mopar OAT Antifreeze/Coolant, MS-90032 (Purple)	13.2-15.0 quarts (12.5-14.2 liters)
Transmission Fluid (8HP75)	ZF LifeguardFluid 8, Mopar ZF 8-Speed ATF, MS-9602	7.0-9.0 quarts (6.6-8.5 liters)
Transfer Case (BW 48-11, 48-12)	Mopar ATF+4 Automatic Transmission Fluid, MS-9602	1.6 quarts (1.5 liters)
Front Differential (DT-spec)	SAE 75W-85 Synthetic Gear & Axle Lubricant, Mopar MS-90084	1.1-1.3 quarts (1.0-1.25 liters)
Rear Differential (DT-spec)	SAE 75W-85 Synthetic Gear & Axle Lubricant, Mopar MS-90084 (w/ LSD additive if applicable)	2.2-2.5 quarts (2.1-2.4 liters)
Brake Fluid	DOT 3 or DOT 4 (MS-4574)	As needed
Power Steering Fluid	Electro-Hydraulic System - No user serviceable fluid	N/A
Washer Fluid	Mopar Windshield Washer Concentrate	1 gallon (3.8 liters)
Diesel Exhaust Fluid	API ISO 22241	5.0 gallons (18.9 liters)

Engine Oil

The 2021 Ram 1500 offers a few engine options, each with specific oil requirements. Using the correct engine oil is paramount for engine longevity and performance, especially with modern emissions systems and variable valve timing.

For the 5.7L HEMI V8 and 3.6L Pentastar V6 engines, the factory-recommended engine oil is SAE 5W-20, meeting API SP or SN Plus specifications. Crucially, it must also meet Mopar Material Standard MS-6395. Many high-quality synthetic and synthetic blend oils meet these specifications. Always check the oil bottle for these specific designations. The 5.7L HEMI typically holds 7.0 quarts (6.6 liters), while the 3.6L Pentastar holds 6.0 quarts (5.7 liters).

For the 3.0L EcoDiesel V6 engine, a very specific oil is required due to its diesel particulate filter (DPF) and other emissions equipment. The specification is SAE 5W-40, meeting API SN Plus/CJ-4/CK-4 and ACEA C3. Furthermore, it must meet Mopar Material Standards MS-10902 or MS-12991. Using an incorrect oil in the EcoDiesel can lead to premature DPF clogging and costly repairs. The EcoDiesel has a capacity of approximately 10.5 quarts (9.9 liters).

Intervals and Pitfalls: Engine oil and filter changes are typically recommended every 10,000 miles or annually, whichever comes first, under normal driving conditions. However, the Ram 1500's onboard Oil Change Indicator System will adjust this interval based on driving style and conditions. For vehicles driven in dusty conditions, extreme temperatures, or frequently used for towing/heavy hauling, more frequent oil changes (e.g., every 5,000 miles or six months) are advisable. Always use a high-quality oil filter that meets OEM specifications.

Engine Coolant

The 2021 Ram 1500 utilizes an Organic Additive Technology (OAT) coolant. The factory fill is Mopar OAT Antifreeze/Coolant, specified by Mopar Material Standard MS-90032. This coolant is typically purple in color. The system capacity generally ranges from 13.2 to 15.0 quarts (12.5 to 14.2 liters), depending on the engine and specific cooling system configuration.

Intervals and Pitfalls: OAT coolants are designed for extended service intervals, often up to 10 years or 150,000 miles. However, it's good practice to inspect the coolant level and condition periodically. Never mix OAT coolant with other coolant types, especially HOAT (Hybrid Organic Additive Technology) coolants, as this can lead to chemical incompatibility, premature corrosion, gel formation, and significant damage to the cooling system components. Always dilute concentrated coolant with distilled water to the manufacturer's recommended ratio (typically 50/50). Using tap water can introduce minerals that can cause scaling and corrosion.

Transmission Fluid

The 2021 Ram 1500 features the ZF 8-speed automatic transmission (8HP75). This transmission requires a very specific fluid. The factory fill is ZF LifeguardFluid 8 or the equivalent Mopar ZF 8-Speed ATF, which meets the transmission manufacturer's specifications and Mopar Material Standard MS-9602. The transmission capacity typically ranges from 7.0 to 9.0 quarts (6.6 to 8.5 liters), depending on whether it's a drain and fill or a complete overhaul.

Intervals and Pitfalls: ZF and Mopar generally consider the transmission fluid to be "fill for life" under normal operating conditions, but they also provide service intervals for severe duty applications, often around 60,000 to 80,000 miles. Many independent shops and enthusiasts recommend changing the fluid more frequently, especially if the vehicle is used for towing, hauling, or frequent stop-and-go driving. Never use generic "universal" Automatic Transmission Fluids (ATF) in the ZF 8-speed transmission. Doing so can lead to shifting issues, accelerated wear, and catastrophic transmission failure. Always use the specified ZF or Mopar fluid.

Transfer Case Fluid

For 4WD and AWD 2021 Ram 1500 models, the transfer case (often a BorgWarner 48-11 or 48-12) requires Mopar ATF+4 Automatic Transmission Fluid, which meets Mopar Material Standard MS-9602. The capacity is approximately 1.6 quarts (1.5 liters).

Intervals and Pitfalls: Transfer case fluid is typically recommended for inspection and possible replacement every 30,000 to 60,000 miles, or more frequently if frequently engaging 4WD/AWD or driving in off-road conditions. Using any other type of fluid could damage the transfer case clutches and gears. While it's technically an ATF, its application here is purely as a lubricating fluid for the transfer case components, not for a transmission with clutch packs.

Differential Fluid

The 2021 Ram 1500 (DT-spec) utilizes specific gear lubricants for its front and rear differentials. Both typically require SAE 75W-85 Synthetic Gear & Axle Lubricant that meets Mopar Material Standard MS-90084. The front differential capacity is generally 1.1–1.3 quarts (1.0–1.25 liters), and the rear differential capacity is 2.2–2.5 quarts (2.1–2.4 liters).

Important Note: If your Ram 1500 is equipped with a Limited Slip Differential (LSD), an additional friction modifier/LSD additive might be required for the rear differential. This is crucial to prevent chatter and ensure proper operation of the limited-slip mechanism. Always check your owner's manual or the build sheet for your specific vehicle to confirm if you have an LSD and if an additive is needed along with the base gear oil.

Intervals and Pitfalls: Differential fluid changes are generally recommended every 30,000 to 60,000 miles, or more frequently for vehicles that regularly tow, haul heavy loads, or drive in demanding conditions. The rear differential, especially with an LSD, works harder and can benefit from more frequent changes.

Brake Fluid

The 2021 Ram 1500 uses a DOT 3 or DOT 4 brake fluid. Mopar specifies a DOT 4 fluid meeting Mopar Material Standard MS-4574. The brake fluid reservoir should be filled as needed to the "MAX" line.

Intervals and Pitfalls: Brake fluid is hygroscopic, meaning it absorbs moisture over time, which lowers its boiling point and can lead to corrosion in the brake system. Many manufacturers recommend flushing the brake fluid every 2-3 years, regardless of mileage. Never mix DOT 3, DOT 4, or DOT 5.1 with DOT 5 fluid, as DOT 5 is silicone-based and incompatible with the glycol-based DOT 3/4/5.1 fluids. Using the wrong fluid type or allowing significant moisture contamination can lead to a spongy brake pedal, reduced braking performance, and costly ABS module repairs.

Power Steering Fluid

The 2021 Ram 1500 is equipped with an Electro-Hydraulic Power Steering (EHPS) system on certain trims/engines or a fully electric power steering system. For an EHPS system, there is typically a special, long-life fluid. For fully electric systems, there is no user-serviceable power steering fluid as the assistance is provided by an electric motor.

Intervals and Pitfalls: If your truck has an EHPS system, consult your owner's manual for the specific fluid type and service intervals. For fully electric systems, no maintenance is needed. Do not attempt to add fluid to a sealed electric system, as this can cause damage.

Washer Fluid

The 2021 Ram 1500 uses standard Mopar Windshield Washer Concentrate or any high-quality pre-mixed automotive windshield washer fluid. The reservoir typically holds around 1 gallon (3.8 liters).

Intervals and Pitfalls: Fill as needed. In colder climates, ensure you use a washer fluid designed for freezing temperatures to prevent the fluid from freezing in the reservoir, lines, or nozzles.

Diesel Exhaust Fluid (DEF)

For 3.0L EcoDiesel models, Diesel Exhaust Fluid (DEF) is essential for the Selective Catalytic Reduction (SCR) system. The DEF used must meet API ISO 22241 specifications. The DEF tank capacity is approximately 5.0 gallons (18.9 liters).

Intervals and Pitfalls: The DEF level is monitored by the vehicle, and warnings will appear on the instrument cluster when the level is low. Always refill with fresh, high-quality DEF. Never use contaminated or expired DEF, as this can damage the SCR system. Store DEF in a cool, dry place and avoid exposing it to direct sunlight or extreme temperatures, which can degrade its quality. If the DEF tank runs empty, the engine's power will be severely limited, or the vehicle may not restart until refilled.

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