Lexus 2012 RX450h Owner's Manual page 755

Engine coolant (RX350)
The coolant level is satisfactory if it is between the "FULL" and "LOW"
lines on the reservoir when the engine is cold.
Coolant selection
■
Only use "Toyota Super Long Life Coolant" or a 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. (Minimum temperature: -31F [-35C])
Canada: "Toyota Super Long Life Coolant" is a mixture of 55% coolant and 45%
deionized water. (Minimum temperature: -44F [-42C])
For more details about coolant, contact your Lexus dealer.
4-3. Do-it-yourself maintenance
Reservoir cap
"FULL" line
"LOW" line
If the level is on or below the
"LOW" line, add coolant up to the
"FULL" line. (P. 930)
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