Arter how many miles does antifreeze have to be changed?

Answer 1

Archaic water/alcohol mix from the 1950s: annually before temperature drops below freezing.

Traditional "green" antifreeze using silicate based corrosion inhibitors: 2 years or 24000 miles.

Extended life coolant (DexCool [inorganic] or OAT or HOAT types Except Honda) using an anti-corrosion salt: 5 years or 100,000 miles.

Honda extended life coolant: first change at 10 years/100000 miles, thereafter 5 years or 50000 miles.

Exception: Vehicles with leaking head gasket or certain Ford vehicles with normal seeping head gasket: before it turns brown/black and stinky.

Exception: Different coolant types (more than one of the above listed five) are mixed: Divide the shortest life listed above by two (in half.)

Exception: Coolant is not of acceptable mixture or is contaminated: immediately.

***Note that if most recent coolant replacement was a "drain and fill" procedure and not a "flush" procedure (except for GM [including Saab and Saturn] or Honda [including Acura]) vehicles the time for replacement should be halved as it was not a complete fluid replacement. Exception to this is if (as is typical at Toyota dealerships) engine block freeze plugs are removed during service. If Freeze plugs are removed, disregard this paragraph.

**** More frequent replacement is generally okay, less frequent replacement may lead to corrosion of or damage to hard parts.