1995 Buick Riviera Owner's Manual - Page 221

Engine Oil If the CHECK OIL LEVEL light on the instrument panelcomes on, it means you need to check your engine oil level right away. It's a good idea to check your engine oil every time you get fuel. In order to get anaccurate reading, the oil must be warm andthe vehicle must be on level ground. CHECK OIL LEVEL For more information, see "Check Oil Level Light" in the Index. You should check your engine oil level regularly; this is an added reminder. 6-12