This paper shows how a breakage probability function for the C-C bonds, elaborated from experimental evidence reported in literature, is introduced in the reactor model for the hydrocracking of Fischer-Tropsch waxes. The results demonstrate a better response to the variation of the operating conditions (especially as concerns temperature) and show product distributions closer to the experimental ones than those predicted by the previous model [Pellegrini, L. A. et al. Chem. Eng. Sci. 2008, 63, 4285]. The agreement with the experimental data has also been enhanced introducing a dependence on temperature (in addition to the dependence on the number of carbon atoms) in the expressions for the Langmuir constants and giving the equilibrium constants for isomerization reactions a new function derived from a thermodynamic study.