Fuel adaptability of a lab-scale 2.5 kW(th) autothermal reforming system was experimentally investigated. Analyses of thermodynamics of autothermal reforming of different fuels at various temperatures were provided to determine the associated flow rates of fuel, air, and steam. The tested reformer has a specifically designed mixing chamber and NiO-Rh based bimetallic catalyst with promoters of Ce, K and La, which were originally designed for autothermal reforming of Jet-A fuel. The adaptability of the reformer to multiple fuels, including diesel, gasoline, ethanol, and methanol was experimentally studied at different operating conditions. Molar fractions of H-2, CO, CO2, and CH4 in the dried reformate were measured and the results were compared with values reported in the literature. The autothermal reforming performance of the reformer for different fuels was evaluated with regard to hydrogen selectivity, CO selectivity, and energy conversion efficiency. It was concluded that the currently developed reformer and the associated catalyst have great fuel adaptability and high potential being used in a fuel-flexible autothermal reforming system. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.