Radiator Coolent Replacement

[ben_t]

I am about to replace my engine coolant. What is the difference between the red and green colour coolants and which one should I use?
Is the BMW brand coolant red or green?

[Bear]

Initally all coolant is colorless, the manufacturer adds color. Personally I used ZEREX G5 in my 1988 750 as it met all EURO Specifications (check the Valvoline website) and is tons less expensive than what BMW sells.

[ben_t]

OK, Just to clear any confusion up (on my part at least).

The green coloured coolant is nitrite, phosphate and amine free but does contain some silicates. It is a hybrid addtitive - mix of both organic and inorganic additives.

The red coloured coolant is silicates, nitrite, phosphate and amine free and uses organic acid additives.

I am still just as confused.

[bryan1970]

BMW coolant is actually a dark greenish blue color. but more blue than green. i guess as lomg as you mix the coolant 50/50 with water is really the main thing to make sure of