1998 Oldsmobile Achieva Owner's Manual - Page 127

BI-LEV: Use on cool, but sunny days. This setting brings in the outside air, but directs it in two ways. The cool air is directed to the upper portion of your body through the instrument panel outlets, slightly but warmer air is directed through the heater ducts and defroster vents. At times this temperature difference may be more apparent than others. The air conditioner compressor is enabledin all three air conditioning positions. Air Conditioning The air conditioner heater work best if you keep and your windows closed while using them. Your vehicle also has the flow-through ventilation system described later in this section. Your system has three air conditioner settings in addition to the standard climate control system. Before using your air conditioneron very hot days, open the windows long enough to lethot inside air escape. This reduces amount of work your air the conditioner's compressor will have to do, which should help fueleconomy. VENT: Use when outside temperatures are mild, and little heating or cooling needed. Airflow comes is through the instrument panel outlets. Set center the control knob tothe temperature desired. HEAT This setting bringsheated air through the heater ducts, and some throughthe windshield defroster vents. If you have the optional engine coolant heater (engine block heater) and use it during cold weather, 0 "F (- 18 O C) or lower, your heating system will more quickly provide heat because the engine coolant is already warmed. See "Engine Coolant Heater" in the Index. Heating On cold days, use HEAT with the temperature knob all the way in thered area. Thesystem will bring in outside air, heat it and send it to the floor ducts. If your vehicle has an engine coolantheater, you can use it to help your system provide warm air fasterwhen it's cold outside (0°F (-18°C) or lower). An engine coolant heater warms the coolant your engine and heating system uses to provide heat. See "Engine Coolant Heater" in the Index. DEFOG: This setting divides airflow equally between the heater ducts and the windshield defrostervents. DEF: This setting directs air through the on windshield defroster vents located top of the instrument panel.