With the darker nights and winter drawing in its time to cast a thought about antifreeze protection for our vehicles, Mainly two types of AF Later cars using OAT corrosion based inhibitors, can be pink or red in color but not always, 5 year change period. Early cars using silicate and nitrate based inhibitors,Ethylene Glycol can be blue or green in color, but not always, 2 year change period Color is not a indication to the type. AF is changed because the inhibitors break down and not the frost protection. Purpose of AF is to lower the freezing point ,raise the boiling point and protect the internals of the cooling system Do not dispose of used coolant down drains etc as highly toxic, 5mm of pure Glycol is enough to kill a cat,so in streams etc will cause havoc to pond life . Inhibitors for both types work differently . OAT has organic acid based metal corrosion inhibitors and come in two forms ,pre mixed and concentrate, the concentrate needs to be mixed with water. Do not use this type on older cars as the acid attacks the gaskets,inc head gasket, seals,and solders, ie in radiators. And veriouse plastics. Only use if your engine is designed to do so. DO NOT USE AS A UPGRADE. Many shops, forecourts,garages even are unaware of the difference. Earlier cars use Ethylene Gyycol also some later cars, these need changing every two years and recommended to flush before replenishing. AF is best mixed with a 50 /50 ratio to water, either a distilled,deironised, or RO water is best, RO water is the cheapest, I paid £7.00 for 40 litres, this can be obtained fron a fish aquatics ,not sure I spelled that right but you get the gist, maybe a pet shop that's fish supporting, or garden centre,you will need a plastic container as the water is pure . Please check your handbook for the correct information. The screen wash needs to be topped up with a wash that provides the correct level of protection against frost,also use RO water to stop smearing and keep washer jets clear, also keeps the bottle from becoming dirty with slime and suchlike.