In this study, the production of fuel and fuel additives from low-viscosity waste renewable mineral oils, called number-10 oil in Turkey, and also of their mixtures, was investigated in detail. The direct addition of these oils and their blends to diesel cause clogging of the fuel pumps of the vehicles due to the crystallization of the waxes present in them, especially at low temperatures. Because of this congestion in the pump, the fuel cannot be pumped to the injectors properly at a constant pressure; this results in incomplete combustion of the fuel, which causes environmental pollution. This problem was solved by developing a simple, economical and environmentally friendly process. It was achieved by blending these oils or their mixtures with suitable solvents and by setting the total oil/total solvent ratio to be at least 1/3 (w/w). Once these oils were blended with suitable solvents or their mixtures, and when the total oil/total solvent ratio was adjusted to be at an optimum, it was noticed that there was no wax crystallization even at very low temperatures down to -35 degrees C. If these mixtures are prepared using these guidelines, they can be used as fuel or fuel additives in diesel- or gasoline-consuming vehicles without causing air pollution and without reducing the performance of the vehicles, while providing fuel savings up to 15%. (c) 2019 Elsevier Ltd. All rights reserved.