The combustion of various C-1-C-2 hydrocarbon mixtures has been experimentally investigated in a continuous perfectly stirred reactor, in a temperature range from 1000 to 1300 K, and at stoichiometric ratio values between 0.5 and 1.5. The concentration values of several molecular species have been measured by GC analysis. The data obtained have been compared with the predictions of two different detailed kinetic models : both fail to predict the experimental trends in various situations : This leads to the conclusion that experimental data based on mixtures of hydrocarbons must be obtained to validate detailed kinetic mechanisms.