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Q: De-ironized water or tap.

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I need to do a coolant change and I'm wondering if it's better to use deironized water mixed 50/50 with antifreeze or use tap water mixed 50/50 with antifreeze , some think it's better to use deironized water ?? Please help.

My car has 86000 miles.
My car has an automatic transmission.

A: You should not use tap water since it has a...

You should not use tap water since it has added chlorine, calcium, and other additives that de-ionized water will not. You can purchase coolant already pre-mixed 50/50 or mix it yourself with de-ionized water and coolant mixed 50/50. You can also use distilled water if you cannot get or find de-ionized water.

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