In-situ crude shale oil, produced by the underground combustion retorting method, was hydrocracked over a nickel--molybdena catalyst at 800/sup 0/F and 1,500 psig. The liquid product was distilled into a low-octane reforming feedstock amounting to 18.5 volume-percent of the in-situ crude plus a large number of small-volume higher boiling fractions and small quantity of waxy residuum. Most of the small-volume distillate fractions were blended into types C-B, T-T, and S-M diesel fuels whose properties resembled those of diesel fuels and distillate fuels now being marketed. The diesel fuels also met the ASTM requirements for diesel fuels and distillate fuel oils with minor exceptions. All of the shale-oil diesel fuels had low sulfur contents and high cetane indexes. The dewaxed distillation residuum was blended with a portion of the small-volume distillate fractions to form a fuel oil fitting the requirements for No. 4 fuel oil except that its viscosity was between the viscosity limits for No. 2 and No. 4 fuels and its pour point of 30/sup 0/F was higher than ASTM recommendations, although in the range of No. 4 fuel oils now being marketed. This fuel oil could also be used as a low-sulfur, high-cetane-index S-M diesel fuel. The yield of diesel fuels was 51.6 volume-percent of the in-situ crude, and the yield of No. 4 fuel oil was 21.5 volume-percent, for a total of 73.1 volume-percent of the in-situ crude that could be used as low-sulfur, high-cetane-index diesel fuels or Nos. 1 through 4 burner fuels. (auth)