2007 Lexus GS 450h User Guide - Page 384

4-3. Do-it-yourself maintenance Coolant The coolant level is satisfactory if it is between the "FULL" and "LOW" lines on the reservoir when the hybrid system is cold. Reservoir cap Full Low If the level is on or below the "LOW" line, add coolant up to the "FULL" line. n If the coolant level drops within a short time after replenishing Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock and water pump. If you cannot find a leak, have your Lexus dealer pressure test the cap and check for leaks in the cooling system. n Coolant selection Only use "Toyota Super Long Life Coolant" or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology. U.S.A.: "Toyota Super Long Life Coolant" is a mixture of 50% coolant and 50% deionized water. (Enabled: -31°F [-35°C]) Canada: "Toyota Super Long Life Coolant" is a mixture of 55% coolant and 45% deionized water. (Enabled: -44°F [-42°C]) For more details about engine/inverter coolant, contact your Lexus dealer. 368