D2 is a refinery abbreviation for Gasoil. It is the second distillate from the crude, and can be used without reformers and additives. So, the first engines used D2 as fuel before petrol cars as we know them today was invented This chemical compound holds the highest amount of energy components and lubricant properties in one mixture and offers the best fuel performance available on the market today. Most scientists agree that grade2 diesel fuel will protect injection pumps, seals, and other important engine parts. D2 is the current standard for all automotive diesel fuel sold in the Union member states and other countries