Hydrocarbons, including motor fuels, such as gasoline [diesel, fuels oils (such as kerosene or No. 2)] and lubricants that are liquid at 60°F and 14.7 (psia) atmospheric pressure.
Although used motor oil is not a petroleum product, per se, for the purposes of this recommended practice, it should be included in the definition of petroleum products as used in the text.
The UST system for the storage of used motor oil does not normally include a pump or product-line to transfer the used oil and is regulated under the UST regulations.
(see API RP1615 - Recommended Practice for the Installation of Underground Petroleum Storage Tanks)