Blind Canyon DECS-6 coal (BC6) was reacted with ground waste rubber tire (WRT) particles and pyrolyzed tire oil (PTO) recovered by vacuum pyrolysis of WRT in an investigation of the feasibility of coprocessing coal and waste tire materials to make transportation fuels. Reactions were carried out in tubing reactors under a 1000 psig (cold) hydrogen atmosphere at either 350 or 430 degrees C for 1 h. Molybdenum catalyst was added in the form of ammonium tetrathiomolybdate, a catalyst precursor. The catalyst precursor was added to obtain a 1% by weight (NH4)(2)MoS4 loading of the reaction mixture. The amount of ground WRT mixed with BC6 was varied to determine the optimum ratio of reactants. A synergistic effect (beneficial effect of reacting coal and WRT together that is not observed when coal and WRT are reacted individually) was observed for most WRT/BC6 reaction mixtures treated at 430 degrees C with catalyst and for some mixtures without catalyst. Coprocessing at 430 degrees C yielded greater total conversion to liquids than at 350 degrees C, with the added advantage of diminishing the amount of carbon black found in the liquid products. BC6 coprocessed with PTO yielded the greatest synergistic effect when reacted at 430 degrees C in the presence of the molybdenum catalyst. The synergism observed for PTO/BC6 reactions may be related to the presence of polyaromatic hydrocarbons (PAHC) in the PTO. It was found that coprocessing coal with PTO is more beneficial than coprocessing coal with WRT, i.e. the BC6/PTO mixture yields more product liquids as well as diminished carbon black contamination of liquid products.