Why do cars use collant instead of water?
Coolant, also known as antifreeze, serves two purposes in a cars
engine.
(1) Coolant keeps the engine cool.
During the summer especially, your engine can get very hot. We
all know that when water gets hot enough, it boils. Have you ever
seen a car on the side of the road, with a bunch of steam blowing
out of the hood? That is a car with an over heated engine. Coolant
can still boil like water, however coolant has a higher boiling
point than water.
(2) Coolant also keeps the engine from freezing.
This is very important. If your cars engine has water in it,
instead of coolant, and the outside temperature drops below
freezing, your engine may become susceptible to becoming frozen. If
your engine freezes from sitting in the cold without coolant, the
water inside of the engine will expand. When ice expands it has to
go somewhere. You engine will crack and will not be repairable.
Coolant can still freeze, but unless your using the lowest grade
coolant, and your driving through Alaska, your coolant probably
won't freeze. How does coolant both keep the engine cool when
running, but keep it from freezing too? Its simple; Coolant has a
higher boiling point than water (99.7'), and it has a lower boiling
point than water (32'). The temperature highs and lows vary with
the type of coolant you use.
!CAUTION! When your coolant level goes down, due to evaporation
or leaks, you may out water in your radiator for a temporary fix.
HOWEVER this alters the highest and lowest points of your coolants
temperature peak. MORE WATER = WATERY COOLANT