Pontiac 2000 Grand Am Owner's Manual page 85

Engine Coolant Heater (If Equipped)
3400 V6 Engine
In very cold weather, 0 _ F ( 18 _ C) or colder, the engine
-
2.4L L4 Engine
coolant heater can help. You'll get easier starting and
-
better fuel economy during engine warm up. Usually,
the coolant heater should be plugged in a minimum of
four hours prior to starting your vehicle.
2-20