Which of the following is not true regarding Ultra Low Sulfur Diesel (ULSD)?

Answer: C — High sulfur kerosene should be used in blending ULSD

The assertion that high sulfur kerosene should be used in blending Ultra Low Sulfur Diesel (ULSD) is not accurate. ULSD is specifically designed to contain significantly lower levels of sulfur compared to traditional diesel fuels. The key feature of ULSD is its maximum sulfur content of 15 parts per million, which serves to reduce harmful emissions when burned in diesel engines. Blending ULSD with high sulfur kerosene would contradict its primary purpose and specification, leading to increased sulfur levels rather than achieving the required standard. In contrast, the other assertions highlight true characteristics of ULSD. Increased production costs are associated with upgrading refineries and processing techniques needed to produce cleaner fuels. Furthermore, some fleets may indeed experience slightly lower fuel economy when switching to ULSD due to the differences in fuel properties. Thus, the statement about using high sulfur kerosene in blending ULSD stands out as incorrect within the context of ULSD's intended use and regulatory framework.