We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, featuring, for two examples, a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and an assessment of the energy content of each distillate fraction. Herein, we compare the distillation curves of four different biodiesel fuel samples to assess possible variations in the distillation curves based on the source of the fuel. Next, we utilize the composition-explicit data channel to characterize distillate cuts of each of the four biodiesel fuels in terms of available energy content. The measure we use for the fluid energy content of each distillate fraction is the composite enthalpy of combustion. On a molar basis, the enthalpy of combustion of the four biodiesel fuels increased slightly with increasing distillation temperature. The biodiesel fuel sample with the highest methyl oleate content had a somewhat different distillation curve and distillate fraction enthalpies of combustion that were higher than those for the other three biodiesel fuels. Then, we compare both the distillation curves and enthalpies of combustion as a function of distillate fraction of the four biodiesel fuels with those for one petroleum-derived diesel fuel. The petroleum-derived diesel fuel is much more volatile than the biodiesel fuels, complete with a difference in initial boiling point of approximately 120 degrees C. Importantly, on a molar basis, the enthalpies of combustion of biodiesel fuels were greater in every distillate fraction compared to those of petroleum-derived diesel fuel; however, on a mass or volume basis, the petroleum-derived diesel fuel sample was more energetic.