Abstract: Disclosed herein are star-shaped macromolecular structures comprising a hyper-branched silicon containing core grafted with a well-defined and controllable number of alkyl (methyl)acrylate (co)polymer arms. The presence of the robust inorganic core provides additional resilience against mechanical degradation and therefore enhanced additive life time. Control over the additive architecture was complemented by tunability of the length of the grafted polymers by making use of controlled radical based polymerization techniques. The performance of these novel inorganic-organic star-shaped hybrids were compared to traditional fully organic lubricant additives. Detailed analysis revealed the multi-functional character of the hybrids by simultaneously performing as bulk viscosity modifiers, boundary lubricant, and wear protectants while being dispersed in a commercially available base oil for automotive lubrication purposes.