Apparently Subaru currently specifies a non-silicate, non-phosphate and non-amine antifreeze. As far as I know Amine hasn’t been commonly used in antifreeze for many years, non-silicate and non-phosphate means not IAT or HOAT so that leaves OAT. But OAT is relatively new and Subaru probably would not have used it prior to the late ‘90s, so what did they use before? I found this comment on one forum ‘To confuse matters further; Subaru doesn't use one type of coolant: Early cars used conventional glycol (IAT), whilst I believe later cars use Hybrid (HOAT). Now I might be wrong, but I think the latest MY08/09 hatchback Impreza uses OAT.’ I hope that clarifies the situation and you can now choose the correct coolant! One thing is sure - you cannot rely on the colour to ascertain what coolant type it is. The colour is simply a dye, and whilst some manufacturers may use one colour to signify a certain type others may use a different colour for the same spec.
