For the 2021 Chevrolet Suburban equipped with the 3.0L 6-cylinder LM2 T Diesel Turbo engine, the required oil viscosity is 0W-20. The engine oil capacity is 7 quarts when performing a change with a new filter. AMSOIL recommends using AMSOIL 0W-20 100% Synthetic Diesel Oil (DP020QT-EA) and a WIX Oil Filter such as WL10351-EA for optimal protection.
What oil does a 2021 Chevrolet Suburban 3.0L Diesel take?
The 2021 Chevrolet Suburban with the 3.0L 6-cylinder LM2 T Diesel Turbo engine requires an oil viscosity of 0W-20 for all temperatures. The AMSOIL lookup oil grade is SEOA5. For vehicles originally using GM Dexos2, the lookup notes that a GM Dexos D licensed engine oil of the appropriate viscosity grade may be used.
AMSOIL product recommendations
Based on the AMSOIL lookup for your 2021 Chevrolet Suburban 3.0L Diesel, the following products are recommended to maintain engine and drivetrain health.
Engine Oil & Filter
| Product Name | Part Code |
|---|---|
| AMSOIL 0W-20 100% Synthetic Diesel Oil | DP020QT-EA |
| WIX Oil Filter | WL10351-EA |
Coolant & Transmission Fluids
| Product Name | Part Code |
|---|---|
| AMSOIL Passenger Car & Light Truck Antifreeze & Coolant | ANTPC1G-EA |
| AMSOIL Propylene Glycol Antifreeze and Engine Coolant | ANT1G-EA |
| AMSOIL Signature Series ULV 100% Synthetic ATF | ULVPK-EA |
Drivetrain & Gear Lubricants
| Product Name | Part Code |
|---|---|
| AMSOIL Signature Series Fuel-Efficient ATF | ATLPK-EA |
| AMSOIL OE Fuel-Efficient 100% Synthetic ATF | OTLQT-EA |
| AMSOIL SEVERE GEAR® 75W-85 Synthetic Gear Lube | SVLPK-EA |
Engine Oil Specifications
| Specification | Detail |
|---|---|
| Viscosity | 0W-20 (All TEMPS) |
| AMSOIL Lookup Oil Grade | SEOA5 |
Engine Oil Capacity & Torque
| Component | Capacity / Torque |
|---|---|
| Oil Capacity (with filter) | 7 quarts |
| Oil Drain Plug Torque | 18 ft/lbs |
Note: After refilling, always check the oil level.
How much transmission fluid does it take?
The 2021 Chevrolet Suburban uses the 10L80 automatic transmission. The capacity varies depending on whether your vehicle is equipped with a cooler. For the 10-speed transmission, the total fill with a cooler is 12 quarts, while the total fill with an O Cooler is 11.5 quarts. An initial fill of 8.1 quarts is also noted.
Automatic Transmission Fluid Details
The AMSOIL lookup note references the WSS-M2C949-A specification (developed by Ford and GM) for this application, noting that products meeting this spec are available under DEXRON ULV and MERCON ULV tradenames.
Transfer Case and Differential Specifications
For transfer case maintenance on models such as the MP3015 or 25 AF6, the capacity is 3.2 pints. The drain plug and fill plug both require a torque of 15 ft/lbs. Always check the tag on the case for identification. For the front differential, the capacity is 2.3 pints.
Common diesel oil-related concerns and how AMSOIL products may help
Diesel engines face unique stresses including high soot loading and temperature extremes. The following table outlines how specific AMSOIL products can support your maintenance needs.
| Concern | Why it matters | AMSOIL Product | How it may help | Limitation |
|---|---|---|---|---|
| Engine Wear | Diesel combustion is high-pressure. | DP020QT-EA | Delivers up to 6X more wear protection than leading industry standards. | Requires regular intervals. |
| Temperature Extremes | Cold starts and high heat affect viscosity. | DP020QT-EA | Excels in hot and cold temperature extremes. | Not confirmed from source data. |
| Heavy Towing Stress | Increases transmission heat. | ULVPK-EA | Withstands rigors of heavy towing and elevated temperatures. | Not confirmed from source data. |
Diesel maintenance notes for this vehicle
- Fuel System: Diesel owners should focus on fuel filtration and diesel exhaust fluid (DEF) management.
- Oil Monitoring: Always check the oil level after refilling to ensure correct capacity.
- Coolant: For concentrated products like ANT1G-EA, mixing with distilled or high-quality water is required.
Common maintenance concerns for this vehicle
Based on owner reports and research, owners of the 2021 Chevrolet Suburban should be aware of several areas:
- Transmission Performance: Some owners have reported erratic shifting or hesitation. While these are unverified complaints, maintaining fluid quality is vital for hydraulic pressure regulation.
- Steering Assist: Software issues in certain models may impact power steering assist at startup.
- Driveline Integrity: Ensure rear driveshaft assemblies are inspected if any sudden loss of drive power occurs.
Recall, TSB, and manufacturer communication notes
The following official NHTSA recall information was identified for the 2021 Chevrolet Suburban. Always verify open recalls by your specific VIN through a certified dealer or the NHTSA website.
- Steering Control Module: A software issue may cause loss of power steering assist (Campaign 21V455000).
- Driveshaft Failure: Certain rear wheel driveshaft assemblies may have improperly heat-treated components (Campaign 22V036000).
- Seat Belt Brackets: Potential issue with front-row center seat belt brackets not being secured to the frame (Campaign 20V792000).
About this vehicle
The 2021 Chevrolet Suburban is part of the twelfth generation of GM’s long-running full-size SUV series. This model year features a 3.0L Inline-6 Diesel engine from the Duramax family, which provides a different maintenance profile compared to the traditional gasoline-based V8 engines often found in this series.
The Suburban is designed for high utility, combining wagon-style body characteristics with a chassis similar to the Chevrolet Silverado pickup truck. It is commonly used for heavy-duty passenger transport, long-distance towing, and large-capacity cargo hauling. Because this vehicle utilizes a compression-ignition diesel engine, maintenance focus should remain on fuel system integrity, specialized oil selection, and cooling system management.
Owners often research the longevity of these vehicles, as the Suburban has a historical reputation for high annual mileage and durability. When maintaining the 3.0L Duramax variant, it is essential to adhere to diesel-specific requirements regarding fluid viscosity and filtration intervals.
Common questions about this vehicle’s diesel oil and maintenance
What is the oil capacity for my 2021 Suburban 3.0L Diesel?
The capacity is 7 quarts when replacing the filter. Always check the level after refilling.
Can I use Dexos2 oil in this diesel engine?
The AMSOIL lookup note states that vehicles originally using GM Dexos2 may use a GM Dexos D licensed engine oil of the appropriate viscosity grade.
What is the correct torque for the oil drain plug?
The confirmed torque specification for the oil drain plug is 18 ft/lbs.
How often should I change my coolant?
AMSOIL products like ANTPC1G-EA offer protection for up to 150,000 miles or 5 years, whichever comes first.
What transmission fluid is required?
The vehicle requires a fluid meeting the WSS-M2C949-A specification (DEXRON ULV/MERCON ULV). AMSOIL lists ULVPK-EA for this application.
Is there a specific gear oil for the front differential?
The capacity for the front differential is 2.3 pints. AMSOIL recommends SVLPK-EA for gear lubrication.
Disclaimer: This information is derived from provided source data. Always consult your owner’s manual or a certified technician to verify specific maintenance requirements and specifications for your vehicle.