Additive packages are used with aviation kerosenes to achieve performance enhancements, such as higher or lower operating temperatures or increased lubricity. An additive that is used to increase operating temperatures for heat sink applications is the +100 additive that is added to JP-8. As part of a large effort on the characterization of JP-8, we measured the effect of the +100 additive on the volatility of JP-8 by use of the composition-explicit or advanced distillation curve approach. We found that the vaporization temperatures increased modestly in the early stages of the distillation but the difference disappeared after the 70% distillate fraction. We tracked selected components of the additive through the distillation curve and related the concentration to the temperature data grid. This allowed us to determine that the heaviest components of the additive are concentrated late in the distillation curve and a significant quantity in the recovered residue. Still incomplete is our understanding of the role and disposition of the oligomer component of the +100 additive. However, some preliminary viscosity and density measurements are provided to suggest what the fate of this component might be.