I had not heard of having
to use distilled water before for mixing coolant
. As that may have just been due to my sheltered existance I have been and checked a number of coolant concentrates from different manufacturers.
Most say just to mix with clean water, the clean part being pretty good sense I would have thought. Found one that said to mix with clean soft water or demineralised - again I would have thought pretty common sense.
But none that said demineralised or distilled water had
to nor even any mention that it should or was preferable to be used.
Maybe other posters have third world water supplies ie harking back to my sheltered existance comment
I wonder how long demineralised or distilled water stays of "demineralised" or "distillled" quality once tipped into an engine? A genuine question.