Water Quality for Mixing with Coolant Concentrate
Engine coolants are a combination of three chemical components:
ethylene glycol (EG) or propylene glycol (PG) antifreeze, inhibiting
coolant additives, and quality water.
Water quality is important to the performance of the cooling
system. Distilled, deionized, or demineralized water is recommended
for mixing with ethylene glycol and propylene glycol base engine coolant
concentrate.
All water used in the cooling system should meet the following
minimum specifications for quality:
|
Chlorides
|
<40 mg/L
|
|
Sulfates
|
<100 mg/L
|
|
Total solids
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<340 mg/L
|
|
Total dissolved I hardness
|
<170 mg/L
|
|
pH
|
5.5—9.0
|
Do not use bottled drinking water because it often
contains higher concentrations of total dissolved solids.
Freeze Protection
The relative concentrations of glycol and water in the engine
coolant determine its freeze protection limit.
|
Ethylene Glycol
|
Freeze Protection Limit
|
|
40%
|
-24 °C (-12 °F)
|
|
50%
|
-37 °C (-34 °F)
|
|
60%
|
-52 °C (-62 °F)
|
|
Propylene Glycol
|
Freeze Protection Limit
|
|
40%
|
-21 °C (-6 °F)
|
|
50%
|
-33 °C (-27 °F)
|
|
60%
|
-49 °C (-56 °F)
|
DO NOT use a coolant-water mixture greater than 60% ethylene
glycol or 60% propylene glycol.
|