Q: Mixing red coolant with green coolant

asked by on September 17, 2017

Is it bad to mix red an green coolant

My car has 197865 miles.
My car has an automatic transmission.

Hi Justin. Thanks for contacting us today. It’s not recommended to mix red and green coolant, as the two different coolant mixtures have different maximum heat ’boiling points’. As coolant heats up, it expands. If it’s not properly mixed with 50% distilled water, it can cause radiator seals to break as heat increases. If the two are mixed, it’s best to drain the radiator and refill with the recommended coolant and distilled water.

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