Oil
Oil is a generic term for a slippery liquid that won't mix readily with water. Oils vary widely in composition but generally consist of mixed organic compounds.
Oils find frequent use as lubricants, fuels, and solvents. Transformers are among the users of oils in these capacities; however, they sometimes consume certain oily substances in larger quantities than strictly required, resulting in impairment of certain functions, disorientation, and temporary mental dysfunction. Though at first it may seem odd, some actively seek these seemingly-deleterious effects. What is odder yet is that humans seek out and consume varying solutions of a certain hydrocarbon with a single hydroxyl group and experience effects quite similar to those mentioned above. Further study is needed to explain this strange coincidence.
Oil is often extracted by oil rigs, and transported in oil tankers and pipelines. All of these are popular targets for Decepticon attacks.
Fiction
The Transformers cartoon
The Decepticons raided an offshore rig drilling for oil, converting the oil into energon cubes. The Autobots arrived to stop them, resulting in the destruction of the rig. While the Decepticons got the Energon cubes, the Autobots managed to save the crew, and started their long friendship with the Witwicky family. More than Meets the Eye, Part 2
When Octane and Trypticon took up residence in Carbombya and began converting its high-quality oil into energon, the nation's dictator Abdul Fakkadi was outraged when he calculated that the conversion rate was 1,000 barrels of oil into a single energon cube.Thief in the Night
Marvel Comics continuity
Head on down to Maccadam's Old Oil House for a pint.
Beast Wars cartoon
Rattrap makes reference to "dirty oil mixed with just a hint of radium" being served in a Cybertronian bar, which is allegedly supposed to make one's head come right off. The same character also references his own desire for "oil and cookies" as a snack he could go for.
Beast Wars II cartoon
Galvatron was a violent oil-oholic, constantly over-energizing and then rampaging. The Strongest Tag Team?
Beast Wars II manga
Tasmania Kid sometimes puts spicy sauce in Apache's oil.Recover the Bonds Lost!
Lio Convoy drinks a bottle of oil called "Convoy Killer" and gets drunk.Recover the Bonds Lost!
Animated cartoon
Bumblebee offered the phrase "Eat crankcase oil!" as an epithet, implying oil from a crankcase is considered less desirable or even unpalatable by Transformers. Home Is Where the Spark Is
Scrapper and Mixmaster enjoy oil from "pint glasses" (barrels) at the "bar" (some random tanker) after a hard day's work. Megatron, however, seems to have specially-made "goblets" for his own stash. The quality of oil could also be analogous to said human alcoholic drinks as Mixmaster says that the Autobots' oil "tastes like water" compared to Megatron's, who calls it his own "private blend". Rise of the Constructicons
Oil also appears to be the equivalent of blood, as a Starscream clone once said to Prowl:"Are you sure that you don't have some Decepticon oil in your tubes?" A Fistful of Energon Another such implication was made, when Bumblebee dressed up as 'Count Dracu-bot' for Halloween, said "I vant to drink your motor oil!" Along Came a Spider Bumblebee has been shown bleeding oil from his arm (as an oil leak), looking very similar to blood dripping from a human's hand. Mixmaster and Scrapper found it delicious. Sari, No One's Home The cannibalistic implications of it functioning as both blood and alcohol are slightly disturbing.
Don't bother heading on down to Maccadam's Old Oil House for a pint. Someone had it closed for "security reasons". This Is Why I Hate Machines
