An evaluation of the influence of two classes of fuels and four types of lubricants on supersonic military interceptor aircraft performance at the airframe subsystem and engine component level is presented. Engine cycles representative of anticipated technology levels in the 1980 time period are analyzed to determine interceptor performance as a function of fuel and lubricant properties and temperature limitations. The relative allotment of available fuel heat sink between engine and airframe is also investigated to determine the primary factors affected by fuel interface temperature and to provide meaningful design guidance for future system applications. The results indicate that with an integrated systems approach to the management of the aircraft and engine system heat loads, JP type fuels and type 2 (MIL-L-27502) lubricants will meet the minimum requirements for advanced military systems. The use of a fuel with JP-7 thermal stability can provide a significant effect on engine performance. Above a minimum level, however, bulk oil temperature has only secondary influence on aircraft performance.