Turbocharger vs Supercharger: What’s the Difference?

Turbochargers and superchargers can sometimes be confused. With “chargers” in their names, it’s easy to confuse turbochargers and superchargers with one-to-one engine devices. However, there are some significant differences that put them on opposite ends of the automotive spectrum.

Before we go into their differences, it helps to understand what connects turbochargers and superchargers from a technical point of view. Turbochargers and superchargers are forced induction systems. These systems use compressors to force compressed air into the engine. The compressed air allows additional oxygen to reach the engine, which contributes to an additional power boost.

The main difference between turbochargers and superchargers is their power source. Turbochargers use the vehicle’s exhaust gas; two fans, a turbine fan, and a compressor fan rotate from the exhaust gas. Conversely, superchargers are driven directly by the engine; a pulley drives gears that turn a compressor fan.

What Is The Difference Between Turbocharger And Supercharger?

“Supercharger” is the generic term for an air compressor used to increase the pressure or density of air entering an engine, providing more oxygen with which to burn fuel. The earliest superchargers were all driven by power taken from the crankshaft, typically by gear, belt, or chain.

A turbocharger is simply a supercharger that is powered instead by a turbine in the exhaust stream. The first of these, dating to 1915, was referred to as turbosuperchargers and were employed on radial aircraft engines to boost their power in the thinner air found at higher altitudes. That name was first shortened to the turbocharger and then to the turbo.

Turbocharger vs. Supercharger: Which Is Better

Essentially, turbochargers and superchargers are air compressors used to increase the flow of oxygen into an engine through forced induction, but each achieves this goal in its own unique way.

Forced induction uses the principle that more air in the combustion process produces greater power output. By compressing air and increasing its density, forced induction allows more oxygen into the engine cylinder, which requires a correspondingly larger amount of fuel. More fuel means bigger explosions in the combustion chamber, resulting in more power production.

At higher altitudes, where the air is less dense, forced induction helps regain lost power by pressurizing air and forcing more oxygen into the cylinders. Without forced induction, an engine is limited by the air density of the atmosphere surrounding it, whether at sea level or 10,000 feet.

What is Turbocharging?

When exhaust gases flow through and rotate a turbine, the turbine creates a vacuum that compresses air before it is forced into an engine’s intake manifold. As the engine spins faster, the turbine spins too, pushing even more air into the engine and increasing power by 25% to 40%.

However, this system is not instantaneous. Because an exhaust-driven turbine takes time to spool up and the turbine must spin at a certain speed for optimal thrust, the system often experiences lag. This lag, known as “turbo lag,” is a momentary drop in performance that occurs as the turbocharger tries to come up to speed.

Turbochargers are not as efficient as superchargers, but because they use recovered energy in the form of exhaust gases, they improve overall engine efficiency. A turbocharger also uses a wastegate that reduces the emission of exhaust gases into the environment.

What is Supercharging?

A supercharger is connected to the engine by a belt or chain. When the engine’s crankshaft rotates, the supercharger spins with it. As with the turbocharger, the spinning creates a vacuum that compresses air and then forces it directly into the engine.

The direct-drive relationship between the supercharger and engine produces a linear powerband that results in a 30% to 50% of instant boost. The supercharger delivers this optimal boost across the entire speed range without delay.

This direct connection to the engine makes compressors more powerful than turbochargers, but also significantly less efficient. Ultimately, they are designed to produce engine power by extracting engine power. In a way, they are like powering an air pump with another air pump.

Also, unlike a turbocharger, a supercharger does not use a wastegate. That means it emits more smog than its turbocharged counterpart.

supercharger vs turbocharger pros and cons Pros

Each of these power-boosting technologies has advantages and disadvantages, but the most obvious difference behind the wheel is a slight delay in how you respond to your right foot in a turbocharged car, especially when you hit the accelerator hard.

That’s because the turbocharger needs a moment to “spool up” before delivering its extra boost of power. It takes a second for exhaust heat and pressure to build up enough to spin the turbo after you step on the accelerator. It’s called “boost lag” or “turbo lag” for obvious reasons.

In contrast, a supercharger has no lag; Because its air pump is connected directly to the engine’s crankshaft, it’s always spinning and responding instantly. The power boost it offers, and with it the engine response you can feel through the seat of your pants increases instantly in direct proportion to how far you step on the accelerator.

While the main disadvantage of the turbo is boost lag, that of the supercharger is efficiency. As a supercharger uses the engine’s own power to turn itself, it siphons off power—more and more of it as the engine speed increases.

For this reason, supercharged engines tend to be less economical in terms of fuel consumption. However, for developing mega-power with instant kick-you-in-the-back throttle response, supercharging applies. It is used by several muscular machines such as the 650hp Chevrolet Corvette Z06 and 755hp ZR1, as well as Dodge’s 700+hp SRT Challenger Hellcats and Demons.

Which Is Better: Turbo- Or Supercharger?

The car manufacturers have decided: that the turbocharger wins by a wide margin. It’s not so much about performance as it is about fuel efficiency. Federal requirements to continually improve fuel economy, stringent greenhouse gas emissions standards, and customer desire for good fuel mileage have driven automakers to use turbos instead of superchargers.

Turbocharging has allowed automakers to replace many V-6 engines with more efficient turbocharged inline-fours that offer at least the same horsepower and often more tire torque, while turbo-sixes power many V-8s in high-performance sports and luxury vehicles.

Global information firm IHS Markit counts about 220 2018 models offering at least one turbocharged engine, versus just 30 supercharged.