An experimental study on autoignition of two binary blends, n-dodecane/1-methylnaphthalene and isocetane/1-methylnaphthalene, has been conducted using a rapid compression machine. Specifically, the ignition delays of the stoichiometric blend+air mixtures were measured at elevated pressures of P-C = 15 bar and 30 bar, compressed temperatures of T-C = 626-944 K, and varying blending ratios of the constituents. For a given set of Pc and T-C, a nonlinear response of the blend reactivity with respect to the relative amount of the constituents was observed. Since a comprehensive chemical kinetic model for the blends investigated here is under development, the current ignition delay datasets serve as the needed targets for model validation. For selected conditions, ignition delay simulations were conducted to highlight and discuss the deficiencies of the literature models and the potential areas for model improvements, especially at low temperatures. Further chemical kinetic analyses were conducted to gain understanding of the blending behavior predicted by the available model. (C) 2017 The Combustion Institute. Published by Elsevier Inc. All rights reserved.