2021 Ford Transit Fluid Type Specs

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil (3.5L EcoBoost V6)	SAE 5W-30 Full Synthetic, Ford WSS-M2C961-A1	6.0 qt (5.7 L)
Engine Oil (3.5L PFDi V6)	SAE 5W-20 Synthetic Blend, Ford WSS-M2C945-B1 / API SP	6.0 qt (5.7 L)
Engine Coolant	Motorcraft Orange, Ford VC-3-D (WSS-M97B44-D2)	12.7–16.9 qt (12.0–16.0 L)
Transmission Fluid (10R80)	Motorcraft MERCON ULV, Ford WSS-M2C949-A	13.0 qt (12.3 L)
Transfer Case (AWD)	Motorcraft Transfer Case Fluid, XL-12	1.5 qt (1.4 L)
Front Differential (AWD)	SAE 80W-90, Ford WSP-M2C197-A	2.5 pt (1.2 L)
Rear Differential	SAE 75W-85, Ford WSS-M2C954-A1	2.5–3.8 pt (1.2–1.8 L)
Brake Fluid	Motorcraft DOT 4 LV, Ford WSS-M6C65-A2	As needed
Power Steering	N/A (Electric Power-Assisted Steering)	N/A
Washer Fluid	-	As needed

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Engine Oil

For the 2021 Ford Transit, the correct engine oil depends on which V6 engine your van is equipped with.

• 3.5L EcoBoost V6: This turbocharged engine requires SAE 5W-30 Full Synthetic motor oil that meets Ford's WSS-M2C961-A1 specification. This is a stringent standard designed for the high-stress environment of a gasoline direct injection (GDI) turbocharged engine. Using an oil that meets this spec, like Motorcraft's own, is critical to prevent low-speed pre-ignition (LSPI) and keep the turbocharger properly lubricated.

• 3.5L PFDi V6: The naturally aspirated V6 uses a more conventional SAE 5W-20 Synthetic Blend motor oil. Look for bottles that list Ford specification WSS-M2C945-B1 or the latest API Donut showing API SP. These oils provide excellent protection for port fuel-injected engines.

Interval: Ford's Intelligent Oil-Life Monitor (IOLM) will tell you when to change the oil, typically between 7,500 and 10,000 miles for normal use. For severe service (heavy towing, excessive idling), expect shorter intervals.

Engine Coolant

The 2021 Transit uses Motorcraft Orange Antifreeze/Coolant, which is an Organic Acid Technology (OAT) coolant. The corresponding Ford specification is WSS-M97B44-D2.

Pitfall: Never mix different coolant types or colors. If you need to top off the system, use only a compatible OAT coolant. Mixing OAT with HOAT (Hybrid OAT, like Ford's older yellow coolant) or IAT (the old green stuff) can cause it to gel, leading to blockages and severe cooling system damage. The initial factory fill is designed to last over 100,000 miles, but it's wise to check the level and condition periodically.

Transmission Fluid

All 2021 Ford Transits are equipped with the 10-speed 10R80 automatic transmission. This advanced transmission requires a very specific, low-viscosity fluid: Motorcraft MERCON ULV (Ultra-Low Viscosity). The Ford specification is WSS-M2C949-A.

Pitfall: This is not a "universal" ATF application. Do not use MERCON V, MERCON LV, or any other type of transmission fluid. Using the wrong fluid will lead to poor shifting, accelerated wear, and eventual transmission failure. The fluid is considered "fill for life" by Ford, but a fluid and filter change between 60,000 and 100,000 miles is cheap insurance against a very expensive repair.

Drivetrain Fluids (AWD & RWD)

Transfer Case (AWD Models)

All-Wheel Drive Transits use a specific Motorcraft Transfer Case Fluid (part number XL-12). It does not use a conventional gear oil.

Front & Rear Differentials

• Front Differential (AWD): The front axle requires SAE 80W-90 gear oil meeting Ford spec WSP-M2C197-A.
• Rear Differential: The rear axle specifies SAE 75W-85 synthetic gear oil that meets Ford specification WSS-M2C954-A1. If your Transit is equipped with a limited-slip differential (LSD), ensure the fluid contains the necessary friction modifier or that you add Motorcraft's friction modifier (part number XL-3).

Brake Fluid

The Transit requires Motorcraft DOT 4 LV High Performance brake fluid, which complies with Ford specification WSS-M6C65-A2. The "LV" stands for Low Viscosity, which is essential for the proper operation of modern ABS and traction control systems, especially in cold weather.

Pitfall: While you can technically use any DOT 4 fluid in a pinch, using a high-quality LV fluid is recommended to maintain the safety systems' designed performance. Brake fluid is hygroscopic (it absorbs moisture), so it should be flushed and replaced every 2–3 years, regardless of mileage.

Other Fluids

• Power Steering: The 2021 Transit uses an Electric Power-Assisted Steering (EPAS) system, so there is no power steering fluid to check or change.
• Washer Fluid: Use any standard blue or orange washer fluid. There is no specific OEM requirement.

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Disclaimer: Fluid capacities can vary slightly based on model configuration, cooling system options, and drain/fill procedures. Always verify specifications and capacities in your owner's manual or with official OEM service information. Capacities listed are approximate fill volumes.

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