Which function does FSII perform to benefit fuel systems?

The function of Fuel System Ice Inhibitor (FSII) in fuel systems primarily revolves around its ability to prevent the formation of ice and the growth of microorganisms in aviation fuels, particularly at low temperatures. This is crucial because the presence of ice can lead to fuel line blockages and other issues that can impair engine performance and safety.

When fuel is exposed to low temperatures, moisture can condense and freeze, forming ice crystals. FSII works by lowering the freezing point of water in the fuel, which in turn prevents ice formation, ensuring that the fuel system operates smoothly even in cold conditions. Moreover, microorganisms such as bacteria and fungi can grow in water that may accumulate in the fuel, leading to the production of algae and sludge that could obstruct fuel filters or corrode fuel tanks. By inhibiting this microbial growth, FSII helps maintain the integrity and reliability of the fuel system.

The other options, while potentially related to fuel properties, do not accurately represent the primary function of FSII in aviation fuel systems.