For the 2023 GMC Sierra 2500 HD Pickup with the 6.6L 8-cylinder L5P Diesel Turbo engine, the required oil capacity is 10 quarts (with filter). The recommended viscosity is 15W-40 for ambient temperatures above -18°C (0°F), though 5W-40 is recommended for all temperatures or to improve cold starting when temperatures are below 0°F. AMSOIL recommends using Signature Series 15W-40 Max-Duty Diesel Oil (DMEQT-EA) paired with an AMSOIL oil filter for optimal protection.
What oil does a 2023 GMC Sierra 2500 HD L5P take?
The 2023 GMC Sierra 2500 HD with the 6.6L L5P diesel engine requires an oil grade of CJ-4. For most operating conditions (above -18°C/0°F), a 15W-40 viscosity is appropriate. However, if you operate in environments where ambient temperatures drop below 0°F (-18°C), AMSOIL recommends using 5W-40 to improve cold starting performance.
AMSOIL product recommendations
Based on the vehicle specifications, AMSOIL provides several high-performance lubrication and filtration options to support the L5P Duramax engine and its heavy-duty applications.
Engine Oil Options
| Product Name | Viscosity | Code |
|---|---|---|
| AMSOIL Signature Series Max-Duty Diesel Oil | 15W-40 / 5W-40 | DMEQT-EA |
| AMSOIL Heavy-Duty 100% Synthetic Diesel Oil | 15W-40 | ADPQT-EA |
Oil Specification: CJ-4
Oil Filter Options
| Product Name | Code |
|---|---|
| AMSOIL Oil Filter | EAO17-EA |
| WIX XP Oil Filter | WL10255XP-EA |
| WIX Oil Filter | WL10255-EA |
Coolant & Transmission Fluid
| Component | Product Name | Code |
|---|---|---|
| Coolant | AMSOIL Passenger Car & Light Truck Antifreeze | ANTPC1G-EA |
| Coolant | AMSOIL Propylene Glycol Antifreeze | ANT1G-EA |
| ATF | AMSOIL Signature Series ULV Synthetic ATF | ULVPK-EA |
Engine Oil Specifications
| Detail | Value |
|---|---|
| Oil Grade | CJ-4 |
| Viscosity (Standard) | 15W-40 |
| Viscosity (Cold Start) | 5W-40 |
Oil Capacity and Service Details
| Detail | Value |
|---|---|
| Capacity (with filter) | 10 quarts |
| Drain Plug Torque | 18 ft/lbs |
| Maintenance Note | Replace drain plug seal during service. Check oil level after refill. |
How much transmission fluid does it take?
The 10-speed automatic transmission in this vehicle has varying capacities depending on whether the unit is equipped with a cooler. The AMSOIL lookup notes that for the 10-speed transmission, the total fill capacity is 20.6 quarts without a cooler, and 22.1 quarts when equipped with a cooler. An initial fill of 14.4 quarts is also noted.
Automatic Transmission Fluid (ATF) Specifications
The AMSOIL lookup note references the WSS-M2C949-A specification, which was developed by Ford and GM; products meeting this are available under DEXRON ULV and MERCON ULV tradenames. For this application, the AMSOIL lookup lists Signature Series ULV 100% Synthetic ATF (ULVPK-EA).
Diesel maintenance notes for this vehicle
Maintaining a high-torque L5P diesel engine requires strict adherence to fluid change intervals and filtration quality. Because these vehicles are often used for heavy towing and commercial work, owners should prioritize:
- Filtration: Using high-efficiency filters like the AMSOIL Oil Filter (EAO17-EA) which provides 99 percent filtering efficiency at 20 microns.
- Cooling System: Monitoring coolant levels and quality to protect all cooling system metals, gaskets, and hoses.
- Cold Weather Prep: Utilizing 5W-40 viscosity in sub-zero temperatures to ensure proper lubrication during startup.
Common diesel oil-related concerns and how AMSOIL products may help
| Concern | Why it matters | AMSOIL Product | How it may help | Limitation |
|---|---|---|---|---|
| Engine Wear | High-pressure diesel environments cause component abrasion. | DMEQT-EA | Delivers up to 6X more wear protection. | Requires regular oil changes. |
| Cold Starting | Thick oil can prevent immediate lubrication in winter. | 5W-40 Viscosity | Improves cold starting at temperatures below 0°F. | Not a replacement for engine block heaters if needed. |
| Contaminants | Small particles can cause significant internal damage. | EAO17-EA | 99% efficiency at 20 microns; greater capacity for small contaminants. | Filter must be replaced per service interval. |
| Heavy Towing Heat | High loads increase transmission fluid temperature. | ULVPK-EA | Withstands rigors of heavy towing and elevated temperatures. | Does not repair existing transmission damage. |
Common maintenance concerns for this vehicle
Based on NHTSA consumer reports, owners of the 2023 GMC Sierra 2500 have noted several areas for attention:
- Powertrain/Transmission: Some owners reported transmission shuddering or alerts regarding a failed valve body.
- Electrical/Battery: Reports exist regarding battery failures and the need for replacement after periods of being parked.
- Engine Power: Instances of “Reduced Engine Power” warnings have been documented, which may relate to various powertrain components.
Note: NHTSA complaints are owner reports and should not be treated as verified defects.
Recall, TSB, and manufacturer communication notes
NHTSA Recall Alert: A recall (Campaign 24V060000) was issued for certain 2020-2024 GMC Sierra 2500 vehicles regarding the power-unlatching tailgate. The electronic gate-release switch may short circuit due to water intrusion, potentially causing the tailgate to unlatch while driving. Dealers will replace the exterior touchpad switch assemblies free of charge.
Important: Owners should verify their specific vehicle’s open recalls by checking the VIN through official GM or NHTSA channels.
About this vehicle
The 2023 GMC Sierra 2500 HD is a heavy-duty pickup truck engineered for high-capacity utility. It is frequently utilized as a medium-duty workhorse, often serving in commercial capacities or for demanding towing and hauling tasks. This model is built on a platform designed to handle significant loads, distinguishing it from light-duty consumer trucks.
At its core is the 6.6L 8-cylinder L5P Diesel Turbo engine. The L5P is part of GM’s heavy-duty diesel ecosystem, known for providing high torque necessary for towing large trailers or managing job-site applications. Because modern diesel engines like the L5P utilize complex emissions systems and turbocharging technology, they require rigorous maintenance. Owners typically focus on fuel system cleanliness, turbocharger health, and maintaining cooling system efficiency to ensure long-term powertrain longevity.
Given its role in heavy-duty environments, maintenance schedules for this vehicle are often more demanding than those for light-duty passenger vehicles. Proper lubrication of the engine, transmission, and cooling systems is critical to managing the heat and stress associated with heavy towing and commercial use.
Common questions about this vehicle’s diesel oil and maintenance
What is the oil capacity for my 6.6L L5P Duramax?
The capacity is 10 quarts when performing an oil change with a new filter. Always check the oil level after refilling.
Can I use 15W-40 in the winter?
If ambient temperatures are above -18°C (0°F), 15W-40 is suitable. However, if temperatures drop below 0°F, AMSOIL recommends using 5W-40 to improve cold starting.
What torque spec should I use for the oil drain plug?
The oil drain plug should be torqued to 18 ft/lbs. It is also recommended to replace the drain plug seal during this service.
Does AMSOIL offer a kit for my Sierra 2500 HD?
Yes, AMSOIL offers several oil change kits, including combinations of Signature Series Max-Duty Diesel Oil with either an AMSOIL filter (EAO17-EA) or a WIX XP filter (WL10255XP-EA).
What should I do if my tailgate unlatches unexpectedly?
This may be related to a known recall regarding the electronic gate-release switch. You should contact a dealer to have the exterior touchpad switch assembly replaced free of charge under the manufacturer’s recall program.
How often should I change my coolant?
While specific intervals depend on usage, AMSOIL provides options like the Propylene Glycol Antifreeze (ANT1G-EA) which offers protection for up to 150,000 miles or 5 years in light trucks.
Disclaimer: This information is derived from provided source data. Always consult your vehicle’s owner’s manual and official GM service documentation before performing maintenance.