2019 Chevrolet Silverado 2500HD Fluid Type Specifications

Quick Reference: 2019 Silverado 2500HD Fluid Specs

Fluid	Type/Spec	Capacity
Engine Oil (6.0L V8)	SAE 5W-30 Synthetic	6.0 qt (5.7 L)
Engine Oil (6.6L Duramax Diesel)	SAE 15W-40 CK-4 (above 0°F) or SAE 5W-40 CK-4 (below 0°F)	10.0 qt (9.5 L)
Engine Coolant	DEX-COOL OAT (Orange)	16.1–22.1 qt (15.2–20.9 L)
Automatic Transmission Fluid	DEXRON VI	~6.0 qt (5.7 L) pan drop
Transfer Case Fluid	DEXRON VI	~2.0 qt (1.9 L)
Front Differential	SAE 75W-90 Synthetic Gear Oil	~1.75 qt (1.66 L)
Rear Differential	SAE 75W-90 Synthetic Gear Oil	~3.0-3.6 qt (2.8-3.4 L)
Brake Fluid	DOT 3	As needed
Power Steering Fluid	DEXRON VI	As needed
Diesel Exhaust Fluid (DEF)	ISO 22241	7.0 gal (26.5 L)
Windshield Washer Fluid	GM Optikleen or equivalent	As needed

Engine Oil

6.0L L96 V8 (Gasoline)

The gasoline V8 engine requires a high-quality full synthetic oil meeting the GM dexos1 Gen 2 specification. The required viscosity is SAE 5W-30. Using oil that meets this spec is critical for the proper function of the engine's variable valve timing (VVT) system and for maintaining warranty coverage. Capacity with a filter change is 6.0 quarts.

• Specification: dexos1 Gen 2
• Viscosity: SAE 5W-30
• Capacity: 6.0 qt (5.7 L) with filter change.

6.6L L5P Duramax V8 (Diesel)

The Duramax diesel has different requirements. It needs a robust, heavy-duty engine oil meeting the API CK-4 certification. GM specifies two primary viscosity grades depending on ambient temperature.

• For temperatures consistently above 0°F (-18°C), use SAE 15W-40.
• For temperatures frequently dropping below 0°F (-18°C), SAE 5W-40 synthetic is recommended for improved cold starting.

Never use gasoline engine oil (like dexos1) in a Duramax, as it lacks the soot-handling capabilities and film strength required for a modern high-torque diesel engine.

• Specification: API CK-4
• Viscosity: SAE 15W-40 or 5W-40
• Capacity: 10.0 qt (9.5 L) with filter change.

Engine Coolant

The 2019 Silverado 2500HD uses a specific Organic Acid Technology (OAT) coolant called ACDelco DEX-COOL. This is easily identified by its orange color. It's crucial not to mix DEX-COOL with other coolant types, such as traditional green IAT (Inorganic Acid Technology) or hybrid HOAT coolants. Mixing can cause the coolant to gel, leading to blockages, overheating, and expensive damage to the radiator, heater core, and water pump.

• Specification: GM 6277M / ACDelco DEX-COOL (OAT)
• Type: Orange, long-life
• Mixture: 50/50 with distilled water
• Capacity: Varies by configuration, typically 16 to 22 quarts. Always verify level after service.

Transmission & Drivetrain Fluids

Automatic Transmission Fluid

All automatic transmissions in the 2019 2500HD, whether behind the gas or diesel engine, require a fluid meeting the DEXRON VI specification. This is a full-synthetic fluid with specific frictional properties for modern GM transmissions. Using a generic "multi-vehicle" ATF or an older DEXRON spec (like DEXRON III) is a common and costly mistake that can lead to harsh shifting, clutch pack damage, and premature transmission failure. A standard pan-drop service will replace approximately 6 quarts.

• Specification: DEXRON VI

Transfer Case Fluid

For 4WD models, the transfer case also uses DEXRON VI automatic transmission fluid. This simplifies service, but it's important not to confuse it with gear oil. Using a thick 75W-90 gear oil in the transfer case will destroy it. Verify the "DEXRON VI" label on the fluid bottle before filling.

• Specification: DEXRON VI

Front & Rear Differential Fluid

Both the front and rear differentials require a high-quality SAE 75W-90 Synthetic Gear Oil. This fluid provides the extreme pressure (EP) protection needed for the ring and pinion gears. While some older trucks required a limited-slip additive for the rear differential, the 2019 2500HD with the G80 locking differential does not require any special friction modifier. Simply use a quality 75W-90 synthetic gear oil. The rear axle capacity is slightly larger than the front.

• Specification: SAE 75W-90 Synthetic Gear Oil

Brake & Power Steering Fluid

Brake Fluid

The hydraulic brake system requires DOT 3 motor vehicle brake fluid. While DOT 4 fluid is compatible and has a higher boiling point, it is not required. Never use DOT 5 (silicone-based) fluid, as it is incompatible with the system's seals. Brake fluid is hygroscopic, meaning it absorbs moisture over time, which can corrode internal components and reduce braking performance. It should be flushed every 2-3 years, regardless of mileage.

• Specification: DOT 3

Power Steering Fluid

The 2019 Silverado 2500HD uses its DEXRON VI automatic transmission fluid in the power steering system. This is a common practice for many modern vehicles. Do not use generic "power steering fluid," which can be chemically different and may damage the system's seals and pump.

• Specification: DEXRON VI

Other Fluids

Diesel Exhaust Fluid (DEF)

For the 6.6L Duramax, you must use high-quality Diesel Exhaust Fluid that is API certified and meets the ISO 22241 standard. Using non-compliant or contaminated fluid can damage the expensive Selective Catalytic Reduction (SCR) system. The DEF tank holds approximately 7 gallons and will need refilling every few thousand miles, depending on driving and towing habits.

• Specification: ISO 22241, API Certified

Windshield Washer Fluid

Use a quality washer fluid rated for the climate in your area. In winter, a fluid with de-icing properties rated for temperatures below freezing is essential to prevent system freeze-up. GM specifies their Optikleen washer fluid, but any quality commercial product will suffice.

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