Thermoplastic molding compositions, comprisingA) at least one thermoplastic polyester A,B) at least one graft polymer B ofb1) a graft base of an elastomeric polymer B1 based on alkyl acrylates, ethylene/propylene, dienes, or on siloxanes, and with a glass transition temperature below 0° C.,b2) a graft B2 composed ofb21) styrene or of substituted styrenes B21 of formula I