50/50 with distilled water.
This depends on the condition of your local tap water...if good fine if not it may deteriate the anti corrosion properties quicker.
Also..lets face it who tops up the radiator with distlled....
There are several types of antfreeze...these types are marketed in different parts ot the world and contenents due to different water properties..
Make sure u have the right sort for your local conditions
Just be sure you didn't purchase pre-mixed coolant
very good point, see that down the workshop a few times....when checking coolant and find is way to dilute....
I do not drive it in the winter.
That makes no difference....If u have low temps, u still dont want water freezing....
If warm winters 20 to 30% coolant
If cold 40 to 50%
BUT..one of the very important properties of antifreeze is anti corrosision, and preventing electoliyis between the different alloys and metals in the engine...
So at the end of the day 40 to 50% regardless.