Castrol Premium Cool Plus is an ethylene glycol based engine coolant concentrate containing a balanced mixture of organic acid and inorganic corrosion inhibitors specially designed to service the requirements of a broad range of heavy duty diesel engines, particularly those with wet liners. Castrol Premium Cool Plus is a low silicate, phosphate and amine free formulation providing extended service life protection for Lead Solder, Aluminium, yellow metal and ferrous alloys. The inclusion of a number of corrosion inhibitors prevents corrosion occurring in the number of dissimilar metals found in modern engine cooling systems. Castrol Premium Cool Plus satisfies or exceeds major industry coolant standards and is satisfactory for use in major U.S., European and Japanese heavy duty diesel engines.