Diesel Fuel Grades
Historically, the quality of automotive fuels in the United States was specified by ASTM standards. Diesel fuels are covered by the ASTM D975 standard.
Since 2004, the D975 standard has covered seven grades of diesel, Table 1. Heavier fuel oils Grade 5 and 6 (residual), which are used primarily for heating purposes, are described by ASTM D39