Atmospheric gasoil is a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms. The AGO distillation cut boils between 420 and 650F (215 - 343C)

The primary use of gasoil is as a blendstock to make diesel or heating oil. However, it must typically go through a hydrotreater first to remove sulfur. Diesel is more typically blended from the lighter end of AGO (Light atmospheric gasoil, or LAGO)

The heavier end of AGO (Heavy atmospheric gasoil or HAGO) can also be fed into the FCC when a refinery is trying to maximize the yield of gasoline over diesel.