With regard to "how much", it depends on your temperature operating range.
Anti-freeze is not a very good heat exchanging fluid, Distilled water is much better at taking the heat away so in hot climates you will get better heat transfer with a leaner mix.
However, as well as providing low temperature protection, anti-freeze also raises the boiling point of the fluid so if your engine is prone to boiling a richer mix can be useful.
As you can see these 2 sort of work against each other in hot climates.
At the other end of the spectrum, the mix needs to be richer to protect the engine from freezing.
At very cold temperatures (-30 celsius) 50% is the norm although you can go up to 60% at a push.
In warmer climes, as low as 30% is better but remember that the anti-freeze is also a lubricant so don't go much below this.
BTW, always use distilled (de-ionised) water in the mix.
Last edited by IvorMog; 23/12/18 09:02 PM.
