2020 Ford F-350 Super Duty Fluid Specifications

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil (6.2L Gas V8)	Motorcraft SAE 5W-30 Synthetic Blend / WSS-M2C946-B1	7.0 quarts (6.6L)
Engine Oil (7.3L Gas V8)	Motorcraft SAE 5W-30 Synthetic Blend / WSS-M2C946-B1	8.0 quarts (7.6L)
Engine Oil (6.7L Power Stroke Diesel)	Motorcraft SAE 10W-30 Diesel Motor Oil / WSS-M2C171-F1 (API CK-4)	13.0 quarts (12.3L)
Engine Coolant	Motorcraft Yellow Antifreeze/Coolant (OAT) / WSS-M97B57-A2	21.3–29.1 quarts (20.1–27.5L) - Varies by engine/options
Transmission Fluid (10R140)	Motorcraft MERCON ULV Automatic Transmission Fluid	18.0 quarts (17.0L) - Service Refill
Transfer Case Fluid	Motorcraft XL-12 Transfer Case Fluid	2.0 quarts (1.9L)
Front Differential Fluid	Motorcraft SAE 80W-90 Premium Rear Axle Lubricant	3.0 quarts (2.8L)
Rear Differential Fluid (Ford Sterling)	Motorcraft SAE 75W-140 Synthetic Rear Axle Lubricant	3.5 quarts (3.3L)
Rear Differential Fluid (Dana M275/M300)	Motorcraft SAE 75W-140 Synthetic Rear Axle Lubricant	4.2–6.4 quarts (4.0–6.1L)
Brake Fluid	Motorcraft DOT 4 LV High Performance Motor Vehicle Brake Fluid	Fill to MAX line on reservoir
Power Steering Fluid	Motorcraft MERCON LV Automatic Transmission Fluid	Fill to MAX line on reservoir
Windshield Washer Fluid	-	Fill as needed
Diesel Exhaust Fluid (DEF)	API Certified ISO 22241	8.0 gallons (30.3L)

Engine Oil

For the 2020 F-350, Ford specifies different engine oils depending on the powerplant. Using the correct oil and viscosity is critical for engine longevity, fuel economy, and proper function of variable valve timing systems.

• 6.2L & 7.3L Gas V8: These engines require Motorcraft SAE 5W-30 Synthetic Blend meeting Ford specification WSS-M2C946-B1. While full synthetic is an excellent upgrade, the oil must meet this Ford spec. Do not use heavier weights like 10W-30 or 5W-20, as this can impede performance and lead to premature wear.
• 6.7L Power Stroke Diesel V8: The Power Stroke has stringent oil requirements. Use a diesel-rated SAE 10W-30 such as Motorcraft Diesel Motor Oil that meets Ford spec WSS-M2C171-F1 and API service category CK-4. The CK-4 rating is essential for protecting modern diesel emission systems. In ambient temperatures consistently below 0°F (-18°C), Ford approves the use of SAE 5W-40 oil also meeting API CK-4.

Engine Coolant

The 2020 Super Duty trucks were factory-filled with Motorcraft Yellow Antifreeze/Coolant, which is an Organic Acid Technology (OAT) coolant meeting Ford specification WSS-M97B57-A2. This coolant is phosphate-free and silicate-free.

Crucial Note: Do not mix coolant types. Never add green, blue, pink, or orange coolants (like the older Motorcraft Orange) to the yellow system. Mixing OAT and HOAT (Hybrid OAT) or IAT (Inorganic Acid Technology) coolants can cause gelling, leading to blockages in the radiator, heater core, and engine coolant passages. If a different color coolant is present, a complete system flush is required. Always use distilled water when mixing with concentrate.

Transmission Fluid

All 2020 Ford F-350s are equipped with the TorqShift 10-speed (10R140) automatic transmission. This transmission exclusively requires Motorcraft MERCON ULV (Ultra-Low Viscosity) automatic transmission fluid.

Pitfall: Do not confuse MERCON ULV with MERCON V, MERCON LV, or any other type of ATF. Using the wrong fluid will cause severe shifting problems and can lead to catastrophic internal transmission damage. This is not a "universal ATF" application. The fluid has a unique friction modifier and viscosity profile specifically for the 10R140's clutches and controls.

Transfer Case Fluid

For 4x4 models, the transfer case requires Motorcraft XL-12 Transfer Case Fluid. It is a specific fluid for Ford transfer cases and should not be substituted with standard gear oil or ATF.

Differential Fluid

• Front Axle: The front differential specifies Motorcraft SAE 80W-90 Premium Rear Axle Lubricant.
• Rear Axle: Most 2020 F-350s use either a Ford Sterling axle or a heavier-duty Dana axle. Both require Motorcraft SAE 75W-140 Synthetic Rear Axle Lubricant. If the truck is equipped with a limited-slip differential (LSD), it is critical to also add Motorcraft Additive Friction Modifier (XL-3) unless the gear oil is explicitly labeled as "limited-slip" ready. Failure to add the friction modifier will cause clutch chatter and binding during turns.

Brake Fluid

Ford specifies Motorcraft DOT 4 LV High Performance Motor Vehicle Brake Fluid. The "LV" (Low Viscosity) is important for the proper response of the ABS and stability control systems, especially in cold weather. While standard DOT 4 can be used in an emergency, the system should be flushed and filled with the correct LV fluid as soon as possible.

Power Steering Fluid

Surprisingly, the power steering system in the F-350 does not use traditional power steering fluid. It is filled with Motorcraft MERCON LV automatic transmission fluid. Do not use MERCON ULV or generic power steering fluid.

Windshield Washer Fluid & DEF

• Washer Fluid: Use any quality commercial windshield washer fluid.
• Diesel Exhaust Fluid (DEF): For 6.7L Power Stroke models, the DEF tank must be filled with high-quality Diesel Exhaust Fluid that is API certified to meet ISO 22241 specifications. Low-quality or contaminated DEF can destroy the expensive SCR (Selective Catalytic Reduction) system. Keep the cap clean and never add anything other than fresh DEF to the tank.

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