Rubber mixtures are disclosed comprising (A) at least one styrene-butadiene rubber, (B) at least one filler and (C) at least one polysulphidic organo(alkyl polyether silane) of the general formula I [(X)(X′)(X″)Si—RI]2—Sm  I. The mixtures are prepared by mixing at least one styrene-butadiene rubber, and at least one filler and one polysulphidic organo(alkyl polyether silane) of the formula (I). The rubber mixtures can be used for the production of mouldings.