Fuel was the term used for a variety of substances, including hypermatter, used to power vehicles. In at least some eras, fuels were divided into grades with shipping grade being seen as one of the lower qualities. This kind earned its name from it use in powering the freighters that ran interstellar commerce, but was also employed in other manners. Peragian fuel was one such. Mined from the Peragus Mining Facility of Peragus II, it was notorious for "wreaking havoc with the engines." It was, however, admitted to "get the job done." Another such fuel was anthracite, which was occasionally left exposed in piles.