Though they are 90-95 percent ethylene glycol based ,all coolants have different additives and anti-corrosive protectants based on the specific material of seals, gaskets ,O-rings and the polymer parts used in the engine.

The replacement coolant formula has to be very much the same , Incompatible coolant mix and we have corrosion,leaks, water pump failure and overheating.

The days of the vintage compatible green coolant are long gone ,now its mostly the Orange OAT (organic acid technology). reign.
mak