1.1 This specification covers seven grades of diesel fuel oils suitable for various types of diesel engines. These grades are described as follows: 1.1.1 Grade No. 1-D S15& This specification covers seven grades of diesel fuel oils suitable for various types of diesel engines. These grades are: Grade No. 1-D S15; Grade No. 1-D S500; Grade No. 1-D S5000; Grade No. 2-D S15; Grade No. 2-D S500; Grade No. 2-D S5000; and Grade