In Real Life, there are many different kinds of car engines. They all sound different, depending on their construction, operation, and even how the intake and exhaust are routed. But the V8 engine has the most distinctive noise of any engine, making it a Stock Sound Effect. This trope is when you hear the distinctive V8 engine noise even coming from cars which shouldn't be making it.
The reasons stem from The Coconut Effect with a dash of Eagleland Creator Provincialism. The specific almost musical burbling of the V8 is specific to American muscle cars, whose V8 engines' cylinders are arranged in two banks at a 90-degree angle to each other, which makes them fire at different rates. This gives the engine two "base" frequencies and makes the sound more melodic. More specifically, this kind of engine was in every car worth having in America in The '60s, so thanks to The Coconut Effect, American creators have come to expect cars to sound like that even when they shouldn't.
This trope is especially common for the bad guys' vehicles. Often whatever engine note the villain's car naturally had will be redubbed with a rumbling V8, because Evil Sounds Deep.
This means the trope applies when you hear the distinctive odd-firing V8 engine even in another V8 car which shouldn't have that noise, like a flat-plane-engined Ferrari or Maserati, to a high-rpm Lotus Esprit V8, to the very distinctive whines of Formula One engines.
- In Sin City, the sound of a V8 engine is said to be vastly different from the sounds of other engines.
- Averted in The Fast and the Furious, where you would expect this to happen considering the cars tend to have 4 or 6-cylinder engines. But the creators really wanted to show off the customization and modifications made to these engines, which sound so unique that they hardly resemble their original counterparts.
- Played straight in Furious 7, where the Lykan Hypersport Dom and Brian jump through a building sounds like it has a Lamborghini V10, when the real-world car has a turbocharged Porsche flat 6.
- The Remake of The War of the Worlds has a first-generation Dodge Caravan, in all its fake wood panel, 4-cylinder engine glory, speeding away in the beginning thrumming out the sound of a V8.
- Back to the Future was a prime offender. The DeLorean normally has a V6 engine (the PRV6), but the makers discovered that it struggled to reach 88 mph in a reasonable time, so they had to replace it with a flax-six engine from a Porsche 911. They still found the need to dub V8 noises over it.
- Never Been Kissed does this with Josie's Buick LeSabre, which has Rob modified to have Tiki Post liveries. In the scene in question, he pulls off to the sound of the V8 burnout.
- An interesting aversion in Bullitt, as both cars involved in the famous chase scene were actually V8-powered, but there is no music in the scene. The only sounds are the amplified roars of the the villains' Charger and McQueen's Mustang GT350.
- Zigzagged in the short film C'était un rendez-vous. Director Claude Lelouch had a Mercedes-Benz 450SEL 6.9, which was already a V8 — but felt the need to dub the sounds of his V12 Ferrari 275GTB. And he punctuates it with very fake-sounding tire squeals.
- This trope appears in Star Wars of all places, with the thrusters of the pod-racers in Episode 1 making noises more akin to contemporary piston engines than jet turbines. In particular, Anakin's pod uses the unedited engine note from a V12 Formula One car, including the exhaust crackles on upshifts note .
- Inverted in Terminator 3: Rise of the Machines, where the V8-powered Lexus SC430 is dubbed over with sounds from a high revving four-cylinder engine (probably a Honda S2000).
- Top Gear has been accused of this, as a way of trying to make their cars sound more exciting. As this sort of thing gets you criticism among car enthusiasts, it's unclear what a car show has to gain from it. They've been known to lampshade the phenomenon, though, such as when Clarkson and May are recruited to make an ad for the Volkswagen Scirocco Diesel, and the Volkswagen people call them out for "enhancing the sound" this way.
- In "Jeremy Clarkson's Thriller", a movie chase scene with a Mini Cooper and a Renault Twingo, both tiny 4-cylinder hatchbacks, is overdubbed with V8 soundtracks. Here, Clarkson also manages to synchronize the exterior and interior sounds perfectly to the action.
- Gold Rush! goes a bit further than usual and dubs the sound of a powerful carburetor-equipped V8 over a diesel engine.
- Averted in Corvette, which uses engine sounds from a real Chevrolet Corvette (reportedly a 1963 Grand Sport).
- In PlanetSide, the Skyguard anti-air buggy makes a heavy, burbling V8 noise when idling and revving, which stands in stark contrast the crappy diesel-sounding four-banger engines in the other buggies, which are ironically faster than the big V8 Skyguard.
- The Crew uses same V8 engine noises for whenever you enter or exit the safehouse or tuner shop and during all cutscenes. While at least a third of the cars on the list are actual V8-powered cars, it doesn't stop your Mini (or Pagani, on the other end of the scale) from sounding like they have race-modded Hemis in them.
- The futuristic space-age combat vehicles of Borderlands 2 use American odd-firing V8 engines.
- Used in Daughter for Dessert when the protagonist and Amanda are taking a road trip to Whiskeyville.
- Some modern German luxury cars do this to appeal to customers, by installing sound actuators which fake the noise or simply playing engine noises through the speakers. Technically, they're supposed to "compensate for acoustic deficiencies" — i.e. help the driver hear the engine and enhance the engine's sound. The noise they make isn't necessarily the classic "TV V8" engine from an American muscle car, but some manufacturers try to make the exhaust note sound more exciting by using white noise to change the engine's acoustics. It's most typically installed on smaller engines, but you also see it on genuine V8 engines (which occasionally deactivate cylinders for improved fuel economy).
- Electric cars might dub over a sound approximating engine noises, because they're particularly quiet — electric motors have very few moving parts. Part of it is for the above-stated reason — for the driver to use audio cues to understand what the car is doing — and part of it is for pedestrians, who are so used to hearing cars that they might not notice a near silent Tesla barreling toward them until it's too late.
- Owners of Rice Burners might make modifications of this sort, usually by means of a cheap exhaust resonator (usually derogatorily referred to as a "Fart Can" due to it making the engine sound like...something else rather than an engine, or simply removing the mufflers altogether
- In general, averted in motorsports, where different cars make different noises, and aficionados like to be able to tell them apart by sound. It's particularly pronounced in multi-class endurance racing, where teams run a myriad of cars that tend to have very varying engines, and viewers are almost expected to be able to differentiate the cars by their exhaust note.