Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from initial boiling point of gasoline to final boiling point of diesel. Recent experimental results have shown WDF by blending 50% gasoline and 50% diesel (G50) exhibits much lower soot emissions than diesel at medium load with relatively low injection ratio with similar thermal efficiency. However, the engine performances fueled by G50 at both low load end and high load end are still unknown. In this study, the combustion and emission characteristics of G50 and diesel have been compared at 1600 r/min and a wide load range from 0.2 MPa IMEP to 1.4 MPa IMEP at a light-duty diesel engine. The results shown that G50 has much lower soot emissions and similar thermal efficiency compared with diesel at high load end. At 0.2 MPa IMEP, G50 exhibits high cycle-to-cycle variation and low thermal efficiency. A three-dimensional engine combustion CFD simulation was conducted by using SAGE combustion coupled with a reduced primary reference fuel reaction mechanism. The simulation results show that the upstream of G50 spray has stronger ambient gas entrainment which improves the fuel vaporization and air-fuel mixing process. The equivalence ratio of the downstream of G50 spray is much lower than that of diesel. For G50, the injection event ends before start of combustion, and the combustion is the spontaneous combustion of premixed charge all along.