LO 11-5 Describe and explain the classification, composition, and applications of various antifreeze formulations

Universal Hybrid Organic Acid Technology Antifreeze
Hybrid organic acid technology (HOAT) is another category of long-life, fully formulated antifreeze that is a combination of some of the inhibitors used in IAT and nitrite/nitrate. This makes HOAT compatible with both light-duty (LD) and HD diesel cooling system materials. Different versions of this anti freeze are dyed colors ranging from orange to straw yellow. Adding nitrite into OAT to prevent cavitation erosion during production is intended to allow marketers to classify HOAT as a universal antifreeze that is useable in all cooling systems. Many engine OEMs do recommend HOAT for a system fill because HOAT uses additives found in conventional IAT, such as nitrite/nitrate, which can be depleted during engine use. The result is that the HOAT additive package must be tested and topped off with an SCA intended for HOAT antifreeze in order to maintain effective cavitation and corrosion protection.