Chevrolet 1998 Prizm Owner's Manual page 249

Engine Coolant
What to Use
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see "Engine Overheating" in
the Index.
A 50/50 mixture of water and the proper coolant will:
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Use a mixture of one-half clean water (preferably
distilled) and one-half coolant that meets GM
Specification 1825-M, which won't damage aluminum
parts. You can also use a recycled coolant conforming
to GM Specification 1825-M with a complete coolant
flush and refill. If you use this mixture, you don't
need to add anything else.
I C ION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture.
With
plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean water and the
proper coolant.
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