If you’ve ever watched a video, read an article, or merely listened to a car nerd rant about cars, you’ve probably heard these terms before: turbocharged, supercharged, and naturally aspirated. Given context, you probably know they have something to do with the engine and, on vibes alone, turbo- and supercharging probably make the car go faster somehow.
But what do these words actually mean? We’re here to demystify.
Naturally Aspirated
Chevrolet Corvette Z06’s Flat-Plane Crank V8
When someone refers to a gas-burning engine as “naturally aspirated,” this simply means that there are no turbochargers or superchargers involved (those two things, by the way, are collectively known as “forced induction”). That’s it. The absence of forced induction is the definition.
This means that air and gas mix, causing little explosions inside cylinders, which in turn cause pistons to move up and down (or sometimes side to side) rapidly, rotating a crankshaft that turns the wheels. That’s the high-level explanation of how a car’s gas engine works.
More simply: gas and air go boom, causing cylinder movement, which causes crankshaft rotation, moving the car forward. And a naturally aspirated engine simply refers to an engine where the boom-creation step isn’t assisted by any sort of fan or air-based trickery.
When someone refers to a gas-burning engine as ‘naturally aspirated,’ this simply means that there are no turbochargers or superchargers involved. That’s it.
As a driver, natural aspiration typically means a more “linear” throttle response, meaning the correlation between how deeply your foot is buried in the gas pedal and how quickly the engine is spinning feels like it’s a straight line. With turbos, this line often feels more curved, making for a less predictable and arguably less organic-feeling driving experience.
The big driving drawback with NA, though, particularly with the most common small-displacement engines, is that you have to rev them out hard to get them to do anything exciting. This has its charms, but it isn’t very fuel-efficient and usually not ideal if all you want out of your car is pure speed.
Within certain enthusiast circles, however, naturally aspirated cars now carry more reverence because of their purer character and image—think cooking on cast iron rather than stainless steel or non-stick. NA is also a rarity these days among new cars, which definitely has something to do with it.
If your car was made before, say, 2012 and wasn’t specifically marketed as a turbocharged, go-faster version, chances are, your engine is naturally aspirated. Over the past decade, however, turbocharging has taken over en masse.
Turbocharging
Toyota GR Corolla’s Turbocharged Three-Cylinder Engine
Photo by: Toyota
A turbocharger is a physical part that sort of looks like a metal snail with a fan in it. It takes exhaust gases that would otherwise be expelled unceremoniously and uses them to spin a fan called a turbine wheel, which in turn spins a second fan called the compressor wheel.
The compressor wheel sucks in ambient air from the outside and pumps it into the combust-y part of the core engine. This results in denser air, which in turn causes more intense explosions and, thus, more power. In a nutshell, a turbocharged engine uses its own exhaust gases to pump more air into itself, creating more intense output.
A key tell (and selling point, depending on who you ask) of turbocharging is the distinct whistling sound that happens when boost builds and that “pshhh” sound that happens when all that compressed air is let out of the blow-off (if there is one) when you take your foot off the gas. “Twin turbos” or “bi-turbo,” by the way, just means an engine that has two turbos on it. Once in a blue Bugatti moon, you might even come across the term “quad turbo,” which is, yes, four turbos.
The important part is that turbos theoretically allow automakers to build new cars that are just as punchy as their old ones, if not punchier, while complying with ever-stricter fuel economy standards. And when driven reasonably or, most crucially, over the EPA test cycle, a smaller displacement turbo engine will be more efficient than a comparable but bigger naturally aspirated one. Drive ‘em harder, though, and your mileage will vary.
[A turbocharger] takes exhaust gases that would otherwise be expelled unceremoniously and uses them to spin a fan called a turbine wheel, which in turn spins a second fan called the compressor wheel.
As driving machines, older turbocharged cars were largely characterized by something called “turbo lag.” Old turbochargers took a while to spool up, and before they did, the engine would feel relatively gutless. But once boost was built, torque would spike fast. This sudden spike in torque was polarizing at best, theatrical in hindsight, and, if we’re honest with ourselves, a little scary mid-corner.
Modern turbocharged cars, however, are almost the opposite. Thanks to developments like smaller, quicker-spooling turbos, direct fuel injection, and perhaps even hybrid electric motor-spooled turbos, torque comes on pretty much immediately and stays there. Little to no lag, no sudden spike, no surprises. This results in a driving character that’s capable no matter where you are in the rev range—step on it and it just goes—but a little boringly so.
Other compromises include increased manufacturing cost and compromised reliability inherent with complicating anything. Modern turbos are getting cheaper and more robust every day, sure, simply because that’s how scale works. But everything else being equal, expect an engine with more parts, more heat, more pressure, and more points of failure to cost more to buy and maintain than one without.
Despite that, turbocharging is basically ubiquitous among new vehicles now, whether you’re talking low-slung supercars, full-size pickup trucks, or small economy hatchbacks. In 2026, a turbocharged four-cylinder has become the standard-issue, regular-person-car engine.
Supercharging
The Ford Mustang GTD’s Supercharged V8
Superchargers, meanwhile, aren’t nearly as common as turbochargers but operate with a similar goal: create more power by compressing more air into the engine. The way it goes about this mission, however, is more mechanical in nature.
A bit like a turbo, superchargers (some people like to call them “blowers”) take ambient air from outside and suck it into the engine for more intense combustion. But instead of exhaust gases doing the spinning, it’s a pulley system attached to the engine’s crankshaft. In other words, the engine not only spins the car’s wheels but also spins the mechanism responsible for feeding it more air—that mechanism is called a supercharger.
There are three main types of superchargers: roots, twin-screw, and centrifugal. The differences between them lie mainly in how they internally move and compress incoming air. Roots and twin-screw both use a pair of long, intermeshing rotors spinning beside each other; a twin-screw is essentially a fancier variation on roots that compresses air internally and is more efficient and stays cooler.
Centrifugal, meanwhile, uses a turbo-like compressor fan called an impeller. Regardless of compression method, the defining characteristic of the supercharger is that the spinny bits are powered by the engine itself via belts and pulleys, not exhaust gases.
Superchargers take ambient air from outside and suck it into the engine for more intense combustion. But instead of exhaust gases doing the spinning, it’s a pulley system attached to the engine’s crankshaft.
Because superchargers are powered by engine movement itself rather than downstream fumes, the additional boost they provide is practically immediate. This means more thrust pretty much regardless of engine speed—roots and twin-screw blowers don’t so much alter how a naturally aspirated engine’s torque curve is shaped, it simply makes it sit higher on the graph.
Because superchargers use the engine to power themselves, their big caveat is worse fuel economy. This parasitic loss means superchargers are pretty much purely a performance play, not an efficiency one.
The supercharger’s most distinctive driving trait, however, might just be the noise they make. It’s a high-pitched whine that’ll sound familiar to anybody who’s ever heard a Dodge Hellcat fly by. It’s a deeply mechanical, primal, borderline unhinged sound, and is a big reason for its popularity with American muscle and muscle-adjacent genres of automobile.
You know that thing that intimidatingly sticks out of, say, the hood of Dominic Toretto’s Charger and has three air holes and a pulley system peeking out? That’s a supercharger.
