Disclosed is a method comprising: (a) mixing in a first mixing step ingredients comprising (i) first polymer, (ii) a low molecular weight polymer having a number average molecular weight of about 5,000 to about 100,000, and (iii) a filler, and (b) mixing in a second mixing step ingredients comprising (i) the mixture obtained in step (a), (ii) a second polymer that is different from said first polymer, and (iii) optionally a filler. In one embodiment, the method further comprises mixing sulfur and vulcanization accelerator(s) into the composition, forming the rubber composition into a sidewall for a tire, and vulcanizing the rubber composition.