The invention relates to a sulphur-crosslinkable rubber mixture, especially for treads of motor-vehicle tyres, and to a motor vehicle tyre. The rubber mixture comprises at least the following constituents: 40 to 100 phr of at least one natural and/or synthetic polyisoprene and 15 phr or more of at least one hydrocarbon resin formed to an extent of 50% to 100% by weight from aliphatic C
5 monomers and to an extent of 0% to 50% by weight from further monomers, where the hydrocarbon resin of the formula I) has a Q of 0.015 [°C-mol/g] to 0.050 [°C-mol/g]: I) Q = softening point [°C]/centrifuge average Mz [g/mol].