The multifunctional behaviour of microcrystalline cellulose (MCC) was tested in emulsion styrene butadiene rubber-silica compounds by studying it as potential reinforcing filler and processing aid. The MCC has been used as silica replacer, and its loading was optimised on the basis of various physicomechanical properties of the experimental compounds. The results show that best performance was achieved at 10% silica substitution. Similar MCC loading was extended to recipes with even higher silica content. At higher silica content, the presence of MCC in mixes had shown reduction in Mooney viscosity, which was favourably used to eliminate one mixing stage but without sacrificing the Mooney viscosity. Peak power consumption during mixing was reduced due to a similar reason. Owing to enhanced plasticity, it was further possible to reduce the aromatic oil content by 3 phr (10·8% as compared to the original oil amount) in the experimental compound to get a Mooney viscosity value equal to control using equal number of mixing stages. Unaged and aged physical properties of the experimental compounds were evaluated and found comparable with the control compound. © 2013 Institute of Materials, Minerals and Mining 2013 Published by Maney on behalf of the Institute.