Severe climates
If you drive in extremely cold climates:
•It may be necessary to increase the coolant concentration
above 50%.
•NEVER increase the coolant concentration above 60%.
•A coolant concentration of 60% will provide improved freeze
point protection. Increased engine coolant concentrations
above 60% will decrease the overheat protection
characteristics of the engine coolant and may cause engine
damage.
•If available, refer to the chart on the coolant container to
ensure the coolant concentration in your vehicle will provide
adequate freeze protection at the temperatures in which you
drive in the winter months.
If you drive in extremely hot climates:
•It is still necessary to maintain the coolant concentration
above 40%.
•NEVER decrease the coolant concentration below 40%.
•Decreased engine coolant concentrations below 40% will
decrease the corrosion/freeze protection characteristics of the
engine coolant and may cause engine damage.
•If available, refer to the chart on the coolant container to
ensure the coolant concentration in your vehicle will provide
adequate protection at the temperatures in which you drive.
Vehicles driven year-round in non-extreme climates should use a 50/50
mixture of engine coolant and distilled water for optimum cooling system
and engine protection.
What you should know about fail-safe cooling
If the engine coolant supply is depleted, this feature allows the vehicle to
be driven temporarily before incremental component damage is incurred.
The “fail-safe” distance depends on ambient temperatures, vehicle load
and terrain.
How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature gauge will move to the red (hot)
area.
Maintenance and Specifications
320
2012 Navigator(nav)
Owners Guide, 1st Printing
USA(fus)
