What Is a Supercharger?
Also known as a blower, this device forces extra air into an engine to give you more power.
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Not to be confused with Tesla’s Supercharger network of EV fast-charging stations, a lowercase-s supercharger is a device that helps an internal-combustion engine take in more air and make more power. Similar to a turbocharger, this device attaches to an engine and provides a form of forced induction, but it works a little differently. Here’s what you need to know.
What Is A Supercharger, And How Does it Work?
A supercharger is a pump driven directly by the internal-combustion engine, either with a belt, chain, or gears, that pressurizes the intake air. Internal-combustion engines suck air and fuel into their cylinders and ignite it, causing little explosions that move the engine’s pistons to turn the crankshaft and, in effect, drive the wheels of the vehicle. To make bigger explosions and more power, you need to cram more air, and more fuel, into the cylinders. One way to do that without increasing the size of an engine (also known as an engine’s displacement) is to use a supercharger to compress the air going into the cylinders.
Automakers have also toyed with the idea of using electric superchargers, which are not mechanically connected to the engine and are instead powered by an electric motor. In most applications, this high-pressure air passes through a heat exchanger called an intercooler to lower its temperature and increase the air’s density. (The denser the air, the more of it will fit into the combustion chamber.)
You’ll often find superchargers atop engines in high-performance vehicles. They’re available from a handful of manufacturers on cars and SUVs such as the Dodge Challenger Hellcat (pictured above), Ford Mustang Shelby GT500, Jaguar F-Type, Land Rover Range Rover Sport, Jeep Grand Cherokee Trackhawk, and Volvo XC90. To give you an idea of how much power a supercharger can add, consider the recent generation of the Range Rover, which debuted with two versions of the same 5.0-liter V-8. The naturally aspirated variant made 375 horsepower, while the supercharged one produced 510 hp. That’s 36 percent more power!
Are There Drawbacks to Supercharging?
You might wonder why more cars don’t use this technology. Well, for one thing, supercharged engines tend to be pretty thirsty, given the engine has to use some of its power to run the blower, and that it’s pushing in more air and fuel than the engine would normally use. Take the 2022 Dodge Charger, for example: a model equipped with the 6.4L V8 is rated by the EPA at 18 mpg combined, while one with a supercharger 6.2L V8 is rated at just 15 mpg.
Superchargers, and vehicles equipped with them, are also more expensive. The units themselves aren’t cheap, nor are the various other upgrades required to increase power by that much while maintaining reliability and emissions compliance.
What’s the Difference Between a Turbocharger and a Supercharger?
Both turbocharging and supercharging are forms of forced induction that increase the amount of air delivered to the engine. But whereas a supercharger runs directly off the engine, a turbocharger uses would-be-wasted energy in a car’s hot exhaust gases to spin its compressor wheel. For this reason, a turbo is more efficient than the supercharger. That said, because a turbocharged engine needs to first build up exhaust gas for the compressor to spin, drivers often notice a lag in power before the engine produces that extra power. In a supercharged vehicle, you’ll have no such problem.
Volvo offers an engine that cleverly combines turbo- and supercharging—sometimes called twincharging—so that one technology offsets the other’s weakness. The supercharger is available from idle, and then the more efficient turbo takes over once it has had time to spool up.
