Heading 2709 covers petroleum oils and oils from bituminous minerals in their crude state — as extracted, without significant refining. Heading 2710 covers oils that have undergone distillation or other refining processes, including gasoline, kerosene, diesel, fuel oil, and lubricating oils. The degree of processing and the resulting product specification determine which heading applies.

Both LNG and CNG fall under heading 2711, which covers petroleum gases and other gaseous hydrocarbons. The US tariff schedule further subdivides 2711 by state (liquefied versus gaseous) and by specific compound (methane, propane, butane, etc.), so the precise tariff line depends on the gas composition and physical state at the time of importation.