In this work, three different combustion modes were obviously observed under different oxygen concentrations, including normal combustion without end-gas autoignition, end-gas autoignition without detonation, and end-gas autoignition with developing detonation for gasoline. The results indicate that the intensities of pressure and pressure oscillation depend on the combustion mode. Compared with hydrogen, gasoline needed higher oxygen concentration or reactivity, and the propensity of end-gas autoignition with developing detonation occurrence was positively related to main flame propagation velocity, however, which needs lower velocity without shock wave to trigger the developing detonation occurrence. Furthermore, the pressure oscillations obtained from two pressure sensors with different locations demonstrated significant difference as detonation occurred, which may provide guidance for the measurement of super-knock intensity in a real engine. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.