Abstract Laminar flame speeds were determined for stoichiometric difluoromethane-air as well as binary mixtures of difluoromethane/tetrafluoropropene and propane/tetrafluoropropene with air using the vertical tube method. To elucidate important reaction pathways, a detailed chemical mechanism has been compiled for modeling these systems as well as other fluorinated methanes and ethanes with air at ambient conditions. The mechanism was constructed from published submechanisms for C3 hydrocarbons and hydrofluorocarbons with additional oxidation chemistry developed for 2,3,3,3-tetrafluoropropene. The latter submechanism contains an additional 10 species and 41 reactions, whereas the entire compiled mechanism contains 132 species and 1088 reactions. The adiabatic, freely propagating laminar flame speeds for mixtures initially at 25oC and atmospheric pressure were computed for difluoromethane, difluoromethane/tetrafluoropropene, and propane/tetrafluoropropene-air mixtures using both the CHEMKIN and CANTERA software packages. Comparisons between experimental data and numerical predictions point to the need for further work; in particular under fuel-lean conditions and for hydrocarbon/hydrofluorocarbon mixtures.