Some things matter. Some things don’t. From the 2020 Chev Silverado owners manual. I use distilled water only for the final flush and even so that’s really just over kill. Admittedly we are Bitogers so carry on.Drinkable tap water has minerals and possibly chlorine. If you flush with that, some will stay in the block as it does not all drain out. Only use water without minerals for filling and flushing.
