Low-grade naphthas, b. 50-260 degrees C, i.e., side streams collected on hydrotreatment of city-grade and aviation-grade fuel oil fractions, were recycled into the stripping column and diesel oil fractions were collected at 335 and 340 degrees C, 0.3 MPa., having S <= 10 ppm, d. 0.629-0.624 g/cm(3), ignition temp. > 62 degrees C, and sediment 0.1 of the admissible value. The hydroraffinates contg. low-grade naphthas were stable for 13 weeks of standard storage, as detd. by absorbance at 400 nm. Exposure to air and sunlight changed color in 3 weeks; UV irradiation did so in 3 hrs.