Through a high-resolution spectroscopic survey, we analyze the velocity field of 16 planetary nebulae with [WC]-or wels-type nuclei in comparison with 8 nebulae having other central star types. We found spectral evidence for finite turbulent velocities in [WC]-type planetary nebulae superimposed on an essentially constant expansion velocity pattern. The nebulae around O-type stars show no evidences for significant turbulence while their expansion velocity is found to increase outwards. Both

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... s of nebulae show the same mean expansion velocity. Our results support the earlier suggestions that nebulae surrounding [WC] central stars are likely related to long-lasting momentum-driven phase bubbles. Turbulence in the nebulae can be either triggered, or enhanced, by stellar wind inhomogeneities that appear ubiquitous in Wolf-Rayet nuclei.