Ethanol fuel for automobiles has been around since many decades — at least since 1978, when Fiat's Brazilian branch developed an ethanol-fueled Fiat 127 in an attempt to cope with the Oil Crisis — with Brazil leading the way in this type of fuel by taking advantage of its vast expanses of sugarcane that can be easily distilled into cane alcohol. While ethyl alcohol packs less energy per volume than gasoline, its many similar physical properties (low density, low boiling point, high volatility, very high flammability and very high anti-knocking index) have made it a very much viable fuel source for combustion engines, which can even be modified to use both gasoline and alcohol indistinguishably, to the point that all cars in Brazil are legally required to run on at least E25 (25% alcohol and 75% gasoline).
However, ethanol fuel still has issues and pitfalls that have prevented its worldwide adoption. First, because alcohol is usually produced by fermenting agricultural crops, there is a very real possibility that a widespread adoption of ethanol fuel might greatly drive up demand of staple foods such as potatoes, corn, wheat or sugarcane and thus greatly increase their price, which could compromise the entire world's food supply; second, in order to run on alcohol, a whole series of engine modifications must be undertaken such as ignition timing re-mapping, special fuel lines, special injectors and alcohol-resistant seals and treatments; and third, because alcohol packs less energy per volume than gasoline, that means it has about 30% less fuel mileage.
And this is where fiction often falls flat at accurately portraying usage of ethanol fuel — from Critical Research Failures such as failing to remember that running a gasoline-only car on ethanol fuel may corrode it internally and risk causing a catastrophic failure, to comically inaccurate depictions such as literally pouring a bottle of whiskey into a car and having it run normally.
Sometimes this is used as a gag about how ridiculously strong the liquor is. Another common gag is that the drink is so potent, using it as fuel actually causes the engine to run better (or at least faster) than it should be able to with regular fuel.
A subtrope of Artistic License Cars, Artistic License Chemistry and Artistic License Engineering. Compare Gasoline Lasts Forever, another trope involving last ditch efforts to get a car to run. Compare also Booze Flamethrower.
- Uncle Scrooge: A variant (in that it does not actually involve alcohol) occurs in "Chugwagon Derby" by Carl Barks. Scrooge and Donald are competing in a vintage car rally and Donald attempts to sabotage Scrooge's car by bribing a gas station attendant to fill Scrooge's tank with contents of a black barrel he points at, even though the attendant tells him that the barrel doesn't contain gasoline. After he fills the tank, Scrooge's car takes off like a rocket, including belching flames.
Scrooge: Man! You must have fueled this car with T.N.T.!... But, then, these old crates will run on almost anything!
Attendant: I'll say! That one's running on weed spray!
- The Adventures of Tintin: Tintin and Captain Haddock are flying a sea plane through a thunderstorm, unfortunately they are almost out of fuel. In a last desperate gambit, Tintin suggests Haddock pour the medicinal spirits in the planes first aid kit into the fuel tank, hoping it will enable them to fly just a bit further and give them the opportunity to land. Unfortunately, Haddock had already drunk them. Inspired by Tintin's comment their running on fumes, he instead forces himself to belch into the tank, his breath already being established to be laced with booze. Sure enough it proves so potent it not just restarts the engine but causes it to catch fire.
- The Rescuers: Played With. At the climax Luke's "swamp juice" is used as to start Madame Medusa's swamp mobile (which previously wasn't getting any gas) so the heroes can escape with Penny.
- Back to the Future Part III: Subverted. Stuck in the old west with no gasoline to power the DeLorean, Doc Brown and Marty attempt this using the strongest liquor they were able to get their hands on. However, all it accomplishes is blowing out their engine.
- The Day After Tomorrow: Discussed. When the British scientists run out of fuel for their generator, one suggests using a bottle of scotch. The head scientist calls him mad for wanting to use a twelve year old scotch for fuel. He then reveals glasses suggesting they drink it instead.
- Get Out & Get Under: Exaggerated. Harold needs gas for his car when he sees a man shoot heroin in the corner. Striking an idea, Harold steals the needle and pours the drug into the car's tank. It not only starts the engine, but suddenly causes the car to speed off by itself, sending Harold on a wild out of control ride.
- The Legend Of The Drunken Master:
- Inverted. The climax of the film takes place at a metalworking factory, which has small containers of kerosene used to heat up the fires enough to melt steel. Against the Final Boss, the hero Wong Fei-hung is seemingly outmatched... until he goes ahead and drinks the kerosene to activates his Drunken Master abilities.
- One (cut out) outtake of the epilogue had Wong suffering badly for that choice, because drinking alcohol with ''that'' high a proof turned out to give him brain damage.
- Down Periscope: Played With. At the climax, the Stingray's chief mechanic pours a bottle of whiskey inside of the (diesel) submarine's gas tank to thin the mixture and make the sub go faster. There's some Truth in Television, as alcohol possesses coolant and anti-detonation properties which, when added to the fuel mixture, allows some forms of combustion engines to be operated at higher than normal power levels. It's also worth noting that he pours himself and the engineer's mate a shot each before dumping the rest into the engine.
- Lawless: At one point, Jack and Forrest run out of gas, which they solve by emptying a jar of moonshine into the gas tank. This gets the car up and running.
- Gamer: In an particularly egregious example John "Kable" Tillman is a death row inmate who must escape from a televised death match against other inmates in which his actions are controlled remotely by a teenage "gamer" through nanites implanted in Tillman's brain. An organization called "Humanz" is pulling strings to aid Tillman in his escape, and have smuggled vodka into his prison for him to use as vehicle fuel. Prior to the match Tillman chugs the vodka to disrupt the nanites and his "gamer's" control over his actions. When combat begins Tillman makes a dash for an abandoned car park where he pukes the alcohol into a 1973 Chevrolet C20 Fleetside gas tank, urinates in the tank, hotwires the car, and speeds away.
- The Gods Must Be Crazy 2: Early on, the bushplane's engine starts sputtering in midair. The pilot grabs a bottle of booze (to the passenger's horror) and proceeds to refuel the plane in flight.
- 1000 Ways to Die: Inverted. A fugitive tries to get drunk by drinking the gasoline from his motorcycle, only to throw up on his campfire and burn himself to death.
- Ark II: One episode has the Ark team encounter starving farmers, who seem capable of producing sufficient grains, namely wheat and corn. However, the local magnate, Lord Lesley, has his thugs terrorize the farmers, and seize their grain stores to synthesize the grain alcohol that powers their vehicles.
- Around The World In Eighty Days: In this 1989 miniseries starring Pierce Brosnan and Eric Idle, the heroes travel from France to Italy in a mini-airship called the Purple Cloud, but run out of fuel halfway and land somewhere in the Alps. Things look bleak until Fogg has the idea of pouring the Cloud's bottle of emergency brandy into the fuel tank. While Passepartout splutters in horror at the prospect of being stranded on an Alp without any brandy, the Cloud takes off again
- The Beverly Hillbillies: In one early episode Jed and Jethro want to go to town, only to discover their faithful truck is empty. Jed resorts to pouring Granny's homemade hooch into the tank. Not only does it work, but its so potent that the truck literally shoots off like the rocket the second Jethro starts the engine.
- The Drew Carey Show: One episode Lewis and Oswald trying to create a beer-powered lawnmower as a promotion for Buzz Beer. All we see is it backfiring.
- The Dukes of Hazzard: Several episodes mention Uncle Jesse's old moonshine is capable of efficiently powering a car. It's specific to his recipe, though.
- Knight Rider: Justified in one episode, Michael and KITT's Mystery of the Week requires them to enter as racers in an alternative fuels competition. One of the competitors is a group of Hillbilly Moonshiners who have converted their car to run on high-proof alcohol. Mechanically inclined moonshiners really do sometimes do this.
- Matt's alleged car in Life in Pieces episode "Interruptus Date Breast Movin'" is so broken that the only thing that starts it is tequila. And by the end of the episode, it bursts into flame.
- Mythbusters: The team tested this in "Moonshiner Myths". They concluded that it is possible for a short while, however, only with extremely high concentrations of ethanol (192 proof); likewise, burning ethanol isn't as efficient or good for the engine as regular fuel. A more detailed summary of the results can be found here.
- The New Avengers: In "Emily", the Avengers are attempting to transport a car to a forensics lab. When an irate farmer shoots at them, he punctures the fuel tank and all the petrol leaks out. Tasked with finding fuel, Purdey and Gambit locate a Hillbilly Moonshiner. After knocking the moonshiner out, they take six gallons of his potent hooch (leaving cash behind to pay for it). They use this to fuel the car to get to their destination.
- BattleTech: Fluff of some ICE (Internal Combustion Engine) vehicles has them able to run on multiple fuel sources, from gasoline to kerosene to ethanol. This has no in-game effects.
- Cyberpunk 2020 and Cyberpunk 2077: Justified example: because of energy crisis issues, many vehicles in the setting utilize a blend of energy-dense alcohols named CHOOH-2 as fuel. (In real life, CH 3 OH is the formula of methanol). The issue of taking from the world's food supply to make fuel was solved by having it made from a special genetically engineered grain that is supposedly highly nutritious, but not even the most powerful world elites will even dare using for food.
- Twilight: 2000: In post-limited nuclear war Europe, many vehicles which used to run on gasoline have been altered so that they can use ethanol.
- Warhammer 40,000:
- Orks are an odd example - their vehicle fuel, while not especially high-grade, is genuinely made for that purpose. The Orks are just tough enough to drink the stuff anyway. Deff Skwadron even depicts Ork aircraft as having their fuel lines running through their cockpits, in case the pilot wants a quick drink mid-flight.
- The Imperial Guard's vehicles are designed to run on anything flammable, from fossil fuels and refined gas giant vapors to alcohols and even wood in some sources, as the STCs used to produce them were designed for use on self-sufficient colony worlds. In the 41st millennium that versatility allows the Imperial war machine to keep running in spite of the Administratum's literal tons of red tape.
- Downplayed in Episode 1 of Back to the Future: The Game. Martys main objective for most of the episode is breaking Doc out of jail by convincing the Emmett Brown of 1931 to finish a working prototype of his Jules Verne-inspired rocket-powered drill. Part of this mission is acquiring a barrel full of 190 proof grain alcohol from a Prohibition speakeasy. In this case, the alcohol on its own is not just poured into the rockets, its the main ingredient for preparing the rocket fuel. Theres even a minigame where Marty must follow young Emmetts instructions to synthesize the fuel, a process involving electrolysis-produced hydrogen getting vented into the distillation barrel and a chemical reaction catalyzed by bacteria-generated nitrogen. And while the result is more effective than the above-mentioned instance of 180 proof whiskey blowing out the DeLoreans fuel injection manifold in Part III of the trilogy, the rockets are inevitably subject to Stuff Blowing Up, as Doc predicted.
- The Nostalgia Critic: Inverted in one of Hyper Fangirl's vlogs, where she says her boyfriend Devil Boner drinks straight gasoline to get drunk.
- Orion's Arm: Vecs (intelligent robots) on the planet of Trip often use alcohol as their fuel. This is a deliberate design choice to encourage vecs to interact with biological people in pubs and similar places, leading to greater social harmony.
- Futurama: All of the robots are fueled by alcohol which many of them, especially Bender, take advantage of to drink incredible proportions (cleaner alternatives like mineral oil exist, but most prefer beer). Without alcohol in their system, they would begin to act like a drunk person. Its a plot point in one episode, that them inefficiently burning alcohol is the reason the future still has problems with global warming.
- Rick and Morty: At the start of the episode "Rickmancing the Stone", Summer takes Rick's flask, takes a swig, and then spits it into the air intake manifold to give the vehicle a nitrous boost.
- The Simpsons: Whilst struggling with temporarily giving up alcohol in Season 4 episode "Duffless", Homer spot's Ralph Wiggum's science project of an alcohol fueled car. He immediately has an Imagine Spot of him pumping "fuel" into both his car and his mouth.
- It's become increasingly common in many countries for gasoline to be blended with small percentages of ethanol, which is commonly called "gasohol". This lets oil companies stretch the non-renewable resource and sell gas more cheaply. However, it's not recommended to put more than 10% ethanol in any vehicle not marked as being Flex-Fuel, as ethanol attracts water and can corrode the plastics in older engines.
- Since 1976, Brazil has been using ethanol (from sugar cane) fueled cars alongside gasoline powered cars. Gas stations have multiple pumps for "Alcool" and "Gasolina", specially once hybrids that run on both (either separately or combined) started to emerge in the 2000s.
- Indy Car racecars used to run on pure methanol for safety reasons (it's much easier to put out a methanol fire than a gasoline fire). In the early 2000s, they were re-engineered to use either a methanol-ethanol blend or pure ethanol (methanol burns with a nearly invisible flame, making it hard to know the extent of a blaze).
- Many soviet military vehicles were specifically designed so that in emergencies they could run on low grade fuels (though not as efficiently) including Vodka, including the Russian Tanks. Likewise many technical fluids used by the Soviet Army were ethyl alcohol-based. Generals accepting the inevitable that their soldiers would try to drink them ensured that mixtures used were safe to drink.
- War Emergency Power allowed engines in military aircraft (particularly during World War II) to be run at higher power settings than the engine's maximum rated power. While this was accomplished via a number of methods, a common one was injecting a water-menthol blend into the fuel mixture. The alcohol was mainly used for its anti-detonation and coolant properties, allowing the engine to be operated at these higher settings with less risk to damaging vital components.