What mixture is used for coolant-antifreeze in hot weather?

Answer 1

Antifreeze mixture is generally the same all year long: 50/50 antifreeze and distilled water (to reduce mineral deposits.)

Extreme conditions can vary the most desirable mixture, but given that modern antifreeze does far more than just prevent coolant from freezing, unless you are certain this is required, a 50/50 mix is best.

Modern antifreeze does a few things:

reduce freezing temperature

increase boiling point

inhibit corrosion

Using a larger percentage of water will slightly improve the native ability of the coolant to carry heat, but since automotive cooling systems are also pressurized, this is minimal.

Using a larger percentage of water will reduce the amount of corrosion inhibiting agents in the coolant, and also reduce the boiling point of the coolant- the reduction in boiling point will have a minimal affect due to, again, the pressurization of the cooling system.

Follow manufacturer requirements, and if you do choose to adjust the mixture, do not go further than 40/60, either way.

One more point: there are numerous different formulations of antifreeze now, and they are generally NOT compatible! Use the correct color/formula for your make of vehicle.