We present three-dimensional hydrodynamical simulations of the fast in-spiral phase of the common envelope interaction between a red giant star and a range of companions with different masses. In order to verify the reliability of the numerics we use two different approaches. The code-to-code comparison shows consistent results. We then compare the outcomes of our simulations to post common envelope systems. At the end of the simulations, most of the envelope of the progenitor is still bound to the system and the orbital separations are systematically larger than those observed. We explain what the reasons for this discrepancy might be and how we will proceed with our investigation.