Equilibrium total conversion of toluene in disproportionaton into benzene and all possible methylbenzenes up to tetramethylbenzenes at 600 K is 58.3 % (conversion into xylenes is 22.7 %), the influence of temperature is very small (total conversion 56.0% at 300 K and 59.4% at 1000 K). This equilibrium is calculated under assumption of possibility of free movement of methyl groups on aromatic ring without any shape selective restriction (xylenes, tri- and tetramethylbenzenes in equilibrium composition), e.g. in liquid phase using F-C catalysts or over mesoporous solid acids as activated aluminas, mesoporous molecural sieves or wide-pore zeolites (Y, dealuminated mordenites). In the case of shape-selective catalysts as H-ZSM-5 zeolite and its various modified forms, the main product in C8 fraction is p-xylene, the creation of tri- and tetramethylbenzenes is restricted, and the total conversion of toluene (smaller than equilibrium) is controlled by diffusion.

The details on equilibrium composition of reaction mixture of toluene disproportionation you can see e.g. in: Stull, D.R., Westrum J.E., Sinke G.C.: The Chemical Thermodynamics of Organic Compounds, New York 1969, p. 163, or in some newer editions…