Availability analysis is applied to cylinder of a spark ignition engine during the combustion process under surrogate fuels (iso-octane, n-heptane, toluene, and methyl-cyclohexane) for gasoline using a two-zone combustion model. Special attention is given to identification and quantification of irreversibility of combustion process basing on the surrogate fuels. This is particularly important since the identification and quantification of irreversibility are not identified in traditional first-law analysis. In identifying these processes, the main differences between second- and first-law analyses are also highlighted. During the combustion process, the availability destroyed by combustion is about 18.9%, and the availability destroyed by the heat transfer is about 12.0%. The survey also reveals that during the whole combustion process shortened combustion duration and postponed ignition are both helpful to reduce availability destruction. (C) 2010 Elsevier Ltd. All rights reserved.