High-temperature (1050-1200 K) pyrolysis studies of pure methylcyclohexane (MCH) and oxidation studies of pure MCH and MCH/toluene blends were performed in the Princeton Turbulent Flow Reactor. Since MCH is a proposed endothermic jet fuel, as well as a possibly significant constituent of current commercial automotive and aviation fuel blends, high-temperature studies of MCH provide an understanding of its decay characteristics in both aircraft and automobile engine environments. Ethene, 1,3-butadiene, methane, and propene were found to be the major intermediates produced by MCH pyrolysis. Oxidation of MCH also produced the same intermediates. As expected, the observed oxidation reaction rates were faster than the pyrolysis reaction rates. The MCH/toluene-blend oxidation experiments (1160 K and Phi = similar to 1.3) revealed that, while the two fuels appear to oxidize by independent mechanisms, the rates of oxidation of both fuels are strongly related to the initial concentration of MCH.