Cooling System 45 Antifreeze or premixed coolant meeting the standards ASTM D 3306 or ASTM D 4656 are primarily for automotive gasoline engines, containing high levels of silicate, and are unacceptable for heavy duty diesel engines . Water and antifreeze should generally be filled as a 50/50 mixture. The mixture should never be less than 40% antifreeze and 60% clean water or more than 60% antifreeze and 40% clean water. Mix the antifreeze/water to the required concentration before adding to the cooling system. The following table gives approximate freezing protection for certain mixtures. W2003082 Note: 60% antifreeze in the mixture gives maximal freeze protection.
To increase the antifreeze content beyond that will only decrease the freeze protection. Freeze Protection Down To: Percentage of Antifreeze in Mixture -13 F (-25 C) -22 F (-30 C) -36 F (-38 C) -51 F (-46 C) 40% 46% 54% 60%