For the 2018 GMC Sierra 3500 Pickup with the 6.6L 8-cylinder L5P Diesel Turbo engine, the oil capacity is 10 quarts (including filter replacement). The preferred viscosity for temperatures above -18°C is SAE 15W-40, though 5W-40 is recommended for all temperatures when ambient conditions are below 0°F (-18°C) to improve cold starting. AMSOIL recommends the Signature Series 15W-40 Max-Duty Diesel Oil paired with an AMSOIL oil filter for optimal protection.
What oil does a 2018 GMC Sierra 3500 6.6L L5P take?
The 2018 GMC Sierra 3500 with the 6.6L Duramax diesel engine requires an oil grade of CJ-4. For most operating conditions where temperatures remain above -18°C (0°F), SAE 15W-40 is the preferred viscosity. In extreme cold, a 5W-40 viscosity is recommended to facilitate easier engine starts.
The total oil capacity for the 6.6L L5P engine is 10 quarts when performing a service that includes replacing the oil filter. It is essential to check the oil level after refilling to ensure accuracy.
AMSOIL product recommendations
Based on the AMSOIL lookup for your 2018 GMC Sierra 3500, the following high-performance fluids and filters are recommended to maintain engine health and performance.
Engine Oil Options
| Product Name | Viscosity | Code |
|---|---|---|
| Signature Series Max-Duty Diesel Oil | 15W-40 | DMEQT-EA |
| Heavy-Duty Synthetic Diesel Oil | 15W-40 | ADPQT-EA |
Note: The AMSOIL lookup lists 5W-40 for use in all temperatures, specifically to improve cold starting when ambient temperatures are below 0°F (-18°C).
Oil Filter Options
| Product Name | Code |
|---|---|
| AMSOIL Oil Filter | EAO52-EA |
| WIX XP Oil Filter | 57202XP-EA |
| WIX Oil Filter | 57202-EA |
Air & Coolant Recommendations
| Component | Product Name | Code |
|---|---|---|
| Air Filter | WIX Air Filter | WA10695-EA |
| Coolant | Passenger Car & Light Truck Antifreeze | ANTPC1G-EA |
| Coolant (Conc.) | Propylene Glycol Antifreeze | ANT1G-EA |
Engine Oil Specifications
| Specification | Details |
|---|---|
| Oil Grade | CJ-4 |
| Preferred Viscosity | 15W-40 (Above -18°C) |
| Cold Weather Viscosity | 5W-40 (All Temps) |
How much oil does it take with a filter change?
Service Specifications
| Metric | Value |
|---|---|
| Oil Capacity | 10 quarts (with filter) |
| Oil Drain Plug Torque | 18 ft/lbs |
Diesel maintenance notes for this vehicle
Maintaining a Duramax L5P engine requires attention to high-stress diesel combustion factors. Key areas of focus include:
- Oil Integrity: Ensure the oil meets CJ-4 specifications to handle heavy-duty loads.
- Filter Efficiency: Using high-quality filters, such as those providing 99 percent efficiency at 20 microns, helps reduce engine wear from small contaminants.
- Cooling System: The coolant capacity is approximately 31.5 quarts. Maintaining proper coolant levels and chemistry is vital for protecting gaskets and hoses.
- Cold Weather Prep: If operating in climates where temperatures drop below 0°F, switch to a 5W-40 viscosity to assist with cold starting.
Common diesel oil-related concerns and how AMSOIL products may help
Diesel engines face unique challenges such as soot loading and extreme thermal stress. 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 | High-pressure combustion causes friction. | Signature Series 15W-40 | Delivers up to 6X more wear protection. | Requires regular oil changes. |
| Cold Starts | Thick oil can hinder lubrication at low temps. | 5W-40 Viscosity options | Improves cold starting in sub-zero temps. | Not a substitute for engine repair. |
| Contaminants | Small particles can cause abrasive wear. | AMSOIL Oil Filter | 99% efficiency at 20 microns. | Must be replaced per interval. |
Common maintenance concerns for this vehicle
Based on owner reports and technical data, owners of the 2018 GMC Sierra 3500 should monitor several systems:
- Electrical & Braking: Some users have reported issues with ABS or Stabilitrak warning lights.
- Fuel System: Monitoring fuel system integrity is critical for modern diesel engines.
- Engine Block Heater: There have been documented recalls regarding engine block heater cords potentially short-circuiting.
Recall, TSB, and manufacturer communication notes
The following official NHTSA recall information has been identified for the 2018 GMC Sierra 3500. Always verify your specific vehicle’s status using your VIN at an authorized dealer or via the NHTSA website.
- Seat Belt Retractor: A recall (Campaign 17V567000) was issued because front seat belt retractor assemblies may have been built with incorrect torsion bars, potentially affecting performance during a crash.
- Engine Block Heater: A recall (Campaign 19V328000) addressed concerns where engine block heater cords or terminals could short circuit, posing a fire risk and potential damage to engine components.
- Fuel Tank Sensor: While specifically noted for gasoline engines in some research, owners should be aware of general fuel system communications regarding sensor accuracy.
About this vehicle
The 2018 GMC Sierra 3500 is a heavy-duty pickup truck designed by General Motors for high-capacity towing and demanding commercial or utility applications. This model is part of the GM heavy-duty lineup, sharing significant mechanical commonality with its sibling, the Chevrolet Silverado.
The heart of this vehicle is the 6.6L 8-cylinder L5P Duramax diesel engine. The L5P is a prominent member of the Duramax family, engineered to handle the high-stress nature of diesel combustion and heavy towing loads. Because these trucks are often used in chassis cab applications or for heavy hauling, maintenance is critical. Owners frequently focus on fuel system integrity, turbocharger maintenance, and specialized Diesel Exhaust Fluid (DEF) requirements common to modern Duramax engines.
As a 3500 series model, the Sierra is built for durability in work environments. However, as with all high-performance diesel vehicles, owners should prioritize regular fluid analysis and adherence to service intervals to manage the effects of heavy-duty operation.
Common questions about this vehicle’s diesel oil and maintenance
What is the recommended oil viscosity for my L5P Duramax?
For temperatures above -18°C, SAE 15W-40 is preferred. If you operate in environments below 0°F (-18°C), use 5W-40 to improve cold starting performance.
How often should I change my oil?
While specific intervals depend on usage, AMSOIL products like the Signature Series are designed to confidently extend drain intervals. Always consult your owner’s manual for primary guidance.
What is the correct oil capacity for an oil and filter change?
The 6.6L L5P engine requires 10 quarts of oil when replacing the filter. Always check the level after refilling.
Can I use a different oil grade?
The AMSOIL lookup note specifies an oil grade of CJ-4 for this application. Using incorrect grades may affect engine protection.
What should I do if my ABS or Stabilitrak light comes on?
NHTSA complaint data indicates some owners have experienced sudden warning lights. This may require professional diagnosis by a certified technician to check the ABS module or electrical systems.
How can I verify if my truck has an open recall?
You should contact a GMC dealer or visit the NHTSA website and provide your Vehicle Identification Number (VIN) to confirm any active recalls, such as those related to seat belts or engine block heaters.
Disclaimer: This information is derived from provided source data. Always consult your vehicle’s owner manual and a certified professional for specific maintenance requirements and to ensure compatibility with your engine components.