I'm a 'it doesn't really matter' sort of guy.
Essentially there are 3 main types, Inorganic Additive (Green), Organic Acid (Pink) and Glycol based (Blue)
There are other colours but these are Hybrid types and not really relevant.
Blue (Glycol) is a great rust inhibitor and is good with alluminium engines, when mixed with water it lowers the freezing point to well below -50C .. before IAT and OAT came along it was the dogs danglies.
Ethelyene Glycol is very poisonous, 50ml (a double) will kill an adult and 4ml a cat or dog.
As we don't have leather seals and lead soldered joints any more I'd 'suggest' you use either Blue (EG based) or Green (IAT).
However it's you car, so you choose.
Essentially there are 3 main types, Inorganic Additive (Green), Organic Acid (Pink) and Glycol based (Blue)
There are other colours but these are Hybrid types and not really relevant.
Blue (Glycol) is a great rust inhibitor and is good with alluminium engines, when mixed with water it lowers the freezing point to well below -50C .. before IAT and OAT came along it was the dogs danglies.
Ethelyene Glycol is very poisonous, 50ml (a double) will kill an adult and 4ml a cat or dog.
As we don't have leather seals and lead soldered joints any more I'd 'suggest' you use either Blue (EG based) or Green (IAT).
However it's you car, so you choose.
You do have lead solder in s3 radiators though.. certainly the early ones
