A detailed chemical kinetic mechanism was used to simulate the oxidation of 1-butene, 2-butene, and isobutene under motored engine conditions. Predicted species concentrations were compared to measured species concentrations obtained from a motored, single-cylinder engine. The chemical kinetic model reproduced correctly the trends in the measured species concentrations. The computational and experimental results showed the main features of olefin chemistry: radical addition to the bond leads to the production of the observed carbonyls and epoxides. For isobutene oxidation, the production of unreactive, 2-methyl allyl radicals leads to higher molecular-weight species and chain termination.