It's dyed so you don't drink it. It's also down to what it's made of. Red is ethylene glycol based, which uses Organic Acid Inhibitor Technology (OAT) . Blue is Monoethylene Glycol based that does not contain nitrates,amines or phosphates so will corrode the aluminum block. Green is used mainly for diesels...I think...yellow is just suspicious.Hi all.
Had my coolant changed and noticed its red.
The car had blue last time.
Does it matter? Or it ts the coolant just dyed for marketing purposes?
Thanks