2003 Subaru Impreza Owner's Manual - Page 140

Instruments and controls NOTE This light does not go out unless the tank is replenished up to an internal fuel quantity of about 4.0 U.S. gal. (15 liters, 3.3 Imp. gal.). J Temperature gauge We recommend that you drive moderately until the pointer of the temperature gauge reaches near the middle of the range. Engine operation is optimum with the engine coolant at this temperature range and high revving operation when the engine is not warmed up enough should be avoided. CAUTION If the pointer exceeds the normal operating range, safely stop the vehicle as soon as possible. See "In case of emergency" in chapter 9. J Ambient temperature gauge (if equipped) The ambient temperature gauge shows the ambient temperature in a range from -22°F to 122°F (-30°C to 50°C). 1) Normal operating range The temperature gauge shows engine coolant temperature when the ignition switch is in the "ON" position. The coolant temperature will vary in accordance with the outside temperature and driving conditions. The gauge can give a false reading under any of the following conditions: D When there is too much sun. D During idling; while running at low speeds in a traffic jam; when the engine is restarted immediately following a shutdown. D When the actual ambient temperature falls outside - CONTINUED - 3-9