In short, the Sierra’s oil capacity depends on the engine: 6 quarts for the 4.3L V6, 8 quarts for the 5.3L V8 and the 6.2L V8, and about 8 quarts for the 3.0L Duramax diesel.
The 2018 Sierra 1500 offered several engine choices, and manufacturers publish different oil capacities based on engine configuration and whether the oil filter is included. The following breakdown covers the common engines in most trims and notes whether the figure includes the oil filter.
Gasoline engine options
The following list shows the oil capacities for the gasoline engines typically found in the 2018 Sierra 1500. Capacities are quoted with the oil filter installed.
- 4.3L V6 EcoTec3: 6 quarts (with filter)
- 5.3L V8 EcoTec3: 8 quarts (with filter)
- 6.2L V8 EcoTec3: 8 quarts (with filter)
Note: Some model variants or service references may list slightly different values, but these are the standard capacities for the 2018 Sierra 1500 gasoline engines.
Diesel engine option
The 3.0L Duramax Turbo Diesel engine typically uses about 8 quarts of oil with the filter in place. The exact figure is specified in the owner's manual for the diesel configuration.
- 3.0L Duramax Turbo Diesel: 8 quarts (with filter)
Concluding reminder: Always verify engine-specific specifications in the owner's manual or on the under-hood label for your exact build, and use the correct amount when performing an oil change with the recommended filter.
Summary
The 2018 GMC Sierra 1500’s oil capacity varies by engine: 6 quarts for the 4.3L V6, 8 quarts for the 5.3L or 6.2L V8, and 8 quarts for the 3.0L Duramax diesel. Check your owner's manual or the under-hood sticker for the precise figure for your specific configuration and oil-change setup.