Re: ?coolant

Posted by Owen_Dyneto On 2009/6/26 9:46:19

Don't have specifics but the primary differences between the red and green and possibly the blue which I'm not familiar with are the corrosion-inhibitor packages and possibly the use of propylene glycol versus ethylene glycol. The former is much more environmentally acceptable, in fact being manufactured and available in an edible food-grade whereas ethylene glycol is quite toxic. The changes in anti-corrosion packages are primarily a result of the majority of modern engines being primarily of aluminum alloys, and radiators primarily plastic tanks on aluminum cores rather than copper. Thus the traditional anti-corrosion packages aimed at copper radiators and cast iron engines (the green stuff) is not optimized for modern engines. Whether the reverse is true (modern antifreezes not optimum for cast iron engines) I don't know, but I continue to use the original "green" formulation in my cars with cast iron engines and copper radiators. The traditional anti-corrosion packages were primarily inorganic silicates and organics of the tolytriazole type.