Standard diesel fuel (sometimes called diesel oil) comes in two grades: Diesel-1 (D1) and Diesel-2 (D2). Diesel or Diesel fuel in general is any fuel used in diesel engines.
That’s why it’s also commonly called as AGO or Automotive Gas Oil. Diesel fuel is a type of fuel derived from the distillation of oil that is heavier than gasoline but lighter than engine oil and
heavy oil.
