When dealing with low-temperature properties of aviation fuels, whatever prediction methods for freezing points may be available in theory, one should rely only on tests such as ASTM D 2386/IP 16 when dealing with aviation fuels. And these should be accompanied by a measurement of viscosities (D 445/IP 71) at low temperatures.
Besides, water icing may be critical. This risk is generally avoided by heating the fuel in the aircraft, or by addition of anti-icing glycol-type chemicals.
Microbiological growth activity may become another risk. Fortunately, it appears that some anti-icing additives aka "fuel system icing inhibitors" (FSII) have biocidal properties.
The technical literature shows that for an ASTM jet fuel A-1 (DERD 2494, NATO F-35)) freezing points are affected by the final boiling point of the fuel in quite a linear manner.
I've seen a graph for A-1 kerosines from ME crudes correlating them. With my old eyes I could discern that a 270 deg C FBP would correspond to a FP -48 deg C. A -50 deg C FP would correspond to a FBP of 265 deg C. I pressume that every crude would should show similar types of correlation.
