A gas oil composition comprising on the basis of the total mass of the composition: an FT synthetic base oil in an amount of 70 percent by volume or more to 98 percent by volume or less; a petroleum base oil in an amount of 2 percent by volume or more to 30 percent by volume or less; and a cold flow improver, comprising an ethylene vinyl acetate copolymer as the active component, in an amount of 20 mg/L or more and 1000 mg/L or lower in terms of the active component, the FT synthetic base oil having a 10% distillation temperature of 170°C or higher and 220°C or lower, a 90% distillation temperature of 280°C or higher and 340°C or lower and an end point of 360°C or lower in distillation characteristics, an higher aliphatic alcohol content of 100 ppm by mass or less, a sulfur content of 1 ppm by mass or less and a total content of normal paraffins having 20 to 30 carbon atoms of less than 7 percent by mass; the petroleum base oil having a 10% distillation temperature of 150°C or higher and 250°C or lower, a 90% distillation temperature of 210°C or higher and 355°C or lower and an end point of 365°C or lower in distillation characteristics, a sulfur content of 10 ppm by mass or less, a total content of normal paraffins having 20 to 30 carbon atoms of less than 6 percent by mass, an aromatic content of 10 percent by volume or more and 60 percent by volume or less and a naphthene content of 10 percent by volume or more and 60 percent by volume or less; the composition having a cloud point of -3°C or lower, a cold filter plugging point of -10°C or lower, a value obtained by deducting the cold filter plugging point from the cloud point of 3°C or higher, a pour point of -12.5°C or lower, a solubility index of 2 or greater, an aromatic content of 2.5 percent by volume or more and 15 percent by volume or less, a cetane number of 50 or greater and 73 or less, and an HFRR wear scar diameter (WS1.4) of 400 μm or smaller. an FT synthetic base oil in an amount of 70 percent by volume or more to 98 percent by volume or less; a petroleum base oil in an amount of 2 percent by volume or more to 30 percent by volume or less; and a cold flow improver, comprising an ethylene vinyl acetate copolymer as the active component, in an amount of 20 mg/L or more and 1000 mg/L or lower in terms of the active component, the FT synthetic base oil having a 10% distillation temperature of 170°C or higher and 220°C or lower, a 90% distillation temperature of 280°C or higher and 340°C or lower and an end point of 360°C or lower in distillation characteristics, an higher aliphatic alcohol content of 100 ppm by mass or less, a sulfur content of 1 ppm by mass or less and a total content of normal paraffins having 20 to 30 carbon atoms of less than 7 percent by mass; the petroleum base oil having a 10% distillation temperature of 150°C or higher and 250°C or lower, a 90% distillation temperature of 210°C or higher and 355°C or lower and an end point of 365°C or lower in distillation characteristics, a sulfur content of 10 ppm by mass or less, a total content of normal paraffins having 20 to 30 carbon atoms of less than 6 percent by mass, an aromatic content of 10 percent by volume or more and 60 percent by volume or less and a naphthene content of 10 percent by volume or more and 60 percent by volume or less; the composition having a cloud point of -3°C or lower, a cold filter plugging point of -10°C or lower, a value obtained by deducting the cold filter plugging point from the cloud point of 3°C or higher, a pour point of -12.5°C or lower, a solubility index of 2 or greater, an aromatic content of 2.5 percent by volume or more and 15 percent by volume or less, a cetane number of 50 or greater and 73 or less, and an HFRR wear scar diameter (WS1.4) of 400 μm or smaller.