For many aspects of engine development, 0D/1D-simulation has evolved into an important tool to obtain reliable results at passable effort, especially for transient operations. Based on the necessary simplification of the three-dimensional reality to one-dimensional models, 1D-simulation heavily depends on the quality of the used sub-models. For internal combustion engines, adequate modelling of combustion chamber processes is of essential importance. Quasi-dimensional approaches to describe burn rates of SI-engines base on the modelling of laminar flame speeds. However, direct measurements of laminar flame speeds are usually taken in the air-fuel equivalence ratio (AFR) range of 0.7 to 1.7 and pressures of only several bar. Common approaches then extrapolate to unsurveyed ranges, which causes contradictory data for laminar flame speed values. To avoid problematic extrapolations into engine-related boundary conditions, reaction kinetics calculations are carried out to determine laminar flame speeds. The therefor used reaction mechanism follows know, physico-chemical principles which allow a mechanism usage outside of its measurement-based validation range. The fuels investigated are gasoline (toluene reference fuel), ethanol and mixtures of both. In the investigation, the influence of octane number and hydrogen/carbon-ratio of gasoline are evaluated. Furthermore, the influences of AFR and EGR are compared. Based on the reaction kinetics calculation, a model of laminar flame speeds is build, which can be used computing-time optimal in 0D/1D-simulation. This model as well as the reaction kinetics calculation results are compared with the widely used Heywood-equation for pure gasoline. As an outlook, calculated flame speeds of gasoline and methane are compared at pressures and temperatures relevant for engine operation to show the necessity of further investigations including test bed measurements.