In order to use gaseous hydrogen for mobility of light and heavy duty vehicles, the standard J2601 from the Society of Automotive Engineers (SAE) recommends that the temperature in the tank must not exceed 85 °C for safety reasons. Prior experiments reported that a vertical thermal stratification can occur during the filling of horizontal tanks under specific conditions. Thermodynamic modeling of hydrogen tank filling can predict the average gas temperature but not the onset of stratification. In a previous study, the computational fluid dynamics (CFD) software OpenFOAM was used to carry out simulations of hydrogen filling for a type IV 37 L tank. The CFD results, by comparison with experimental results, were capable to predict the rise of the thermal stratification with however an underestimation of thermal gradient magnitudes. The maximal temperature predicted at the end of the filling was 15.05 °C bellow the experimental measurements. In this work, the k − ω SST turbulence model is replaced by the k − ω SST SAS turbulence model to limit the prediction of high levels of eddy-viscosity in stagnation areas which over-diffuses the temperature. By using the same mesh as in the above mentioned study, (651 482 cells in the fluid region and 449 126 cells in solid regions), the k − ω SST SAS turbulence model is found to be more appropriate for CFD simulation of tank filling as it predicts a thermal gradient magnitude in the gas in better agreement with experimental measurements than the k − ω SST turbulence model for a similar time of simulation. The maximal temperature predicted at the end of the filling is 2.17 °C bellow the experimental measurements.