Lexus LS 460 2017 Manual page 642

642
7-2. Steps to take in an emergency
The coolant level is satisfactory if
4
it is between the "FULL" and
"LOW" lines on the reservoir.
Reservoir
1
"FULL"
2
"LOW"
3
Add coolant if necessary.
5
(P. 541)
Water can be used in an emergency if
coolant is unavailable.