2710.20.10 - Testing 25 degrees A.P.I. or more

This HTS category, 2710.20.10, specifically covers distillate and residual fuel oils, including blended fuel oils, that have a testing gravity of 25 degrees A.P.I. or more. This gravity measure indicates a relatively lighter oil compared to those with a lower API gravity. These products are derived from petroleum or bituminous minerals and serve primarily as fuels, distinguished by their specific gravity.

It is important to differentiate this classification from its sibling category, 2710.20.05, which encompasses similar fuel oils but tests *under* 25 degrees A.P.I. Therefore, the defining characteristic for this particular sub-heading is the higher API gravity, signifying a different density and potentially distinct applications or refining processes.

Within this classification, further subdivisions exist based on viscosity. Subcategories are provided for oils with a Saybolt Universal viscosity at 37.8°C of less than 45 seconds (light fuel oils), those with a viscosity between 45 and 125 seconds (No. 4-type fuel oils), and finally, heavy fuel oils with a viscosity exceeding 125 seconds (2710.20.10.50). These viscosity measurements are crucial for determining the intended end-use and handling requirements of the fuel oil.