A relatively small detailed mechanism has been developed for the combustion of various fuels, mainly hydrocarbons, in air or oxygen-inert mixtures. This mechanism has been tested previously for autoignition, premixed-flame burning velocities, and structures and extinction of diffusion flames and of partially premixed flames of many of these fuels. While submechanisms for hydrogen and carbon monoxide are essential components of this mechanism, thorough testing of the predictions of the mechanism for these simpler fuels has not been performed recently. Such testing is reported here and leads to modifications of rate parameters for a few of the most important elementary steps, as well as to deletion of one reaction and addition of another. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved.