The effect of 1-octanol blending on the multi-stage autoignition of conventional diesel and HVO fuels

•The autoignition process for blends of 1-octanol with conventional diesel and HVO was studied in a CVCC and a modified CFR engine.•Blending 1-octanol into conventional diesel and HVO increased the ignition delay in the CVCC, especially at low initial chamber temperatures.•While ignition in the CVCC is chemically controlled, the spray diffusion process affected the observed combustion speed and chamber pressure at ignition.•In the CFR engine, 1-octanol blending enhanced the reactivity of conventional diesel fuel as a result of its high propensity for ITHR.