The kind of oil the 2018 GMC sierra takes iS5w-30. Having high quality oil is key for the engine to run smoothly. You will run into issues with the oil at some point. Knocking noise may show up from the engine. Bad oil can cause the engine to stop working. A common problem is an awful burning smell. This needs to be inspected as soon as possible or the car might explode. You could experience bad gas mileage. Your oil needs to be replaced eventually. Every 5,000 to 10,000 miles is a good rule of thumb. If You don't replace it, there will be issues with the engine.
Oliver A.
August 29, 2019
Those of the 2018 GMC Sierras that have a 5.3 liter engine, the Sierra crew cab SB, the SLT (crew cab and double cab) SB the SLE crew cab SB and the Denali (with a 5.8FT SB or a 6.6FT SB), use 0w-20 oil. Similarly, the 4.3 liter trucks all use 5w-30. Those truck are the Sierra (double cab or regular cab) SB, the Sierra regular cab LB, the Sierra Crew cab SB, the SLE double cab SB, the SLE regular cab (short and long bed) and the SLE crew cab SB.
The Questions and Answers on this page are the statements and opinions of their respective authors and not VehicleHistory.com. VehicleHistory.com
does not research or authenticate any of the Answers provided.