Buick Regal 2018 Owner's Manual page 356

Service and Maintenance 355
Maintenance Schedule
Additional Required
Services - Normal
Rotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.
Replace passenger compartment air filter. (1)
Inspect evaporative control system. (2)
Replace engine air cleaner filter. (3)
2.0L Engine: Replace spark plugs. Inspect spark
plug wires.
3.6L Engine: Replace spark plugs. Inspect spark
plug wires.
Drain and fill engine cooling system. (4)
Visually inspect accessory drive belts. (5)
Replace brake fluid. (6)