Buick 1994 LeSabre Owner's Manual page 231

Let the warning lights work as they should.
What to Use
Use a mixture of one-half clean water (preferably
distilled) and one-half antifreeze 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
NOTICE:
If you use an improper coolant mix, your engine
could overheat and be badly damaged. The
repair cost wouldn't be covered by your
warranty. Too much water in the mix can freeze
and crack the engine, radiator, heater core and
other parts.
Adding Coolant