Diesel Technician Practice Test

Premium long-life antifreeze formulations that utilize organic acids typically have different corrosion protection requirements compared to older formulations. The primary reason for this is that the organic acid technology (OAT) relies on carboxylate-based inhibitors, which do not require nitrite for protecting against corrosion inside the engine components.

In older formulations, nitrite was often used as a corrosion inhibitor, especially for protecting iron and aluminum components. However, with the transition to newer organic acid formulations, the need for nitrite has significantly diminished. These modern formulations provide adequate protection without requiring higher levels of nitrite.

As a result, these newer antifreeze products can operate effectively with much lower or even zero nitrite content. This shift not only meets the performance needs but also aligns with environmental and safety considerations, leading to the use of lower levels of nitrite in comparison to older antifreeze formulations.