Turbocharger vs. Supercharger – What’s the Difference?

The turbocharger was first created in 1905 by Alfred Buchi, a Swiss engineer. However, it wasn’t until 1962 that a turbocharger was used in a production car. That car was the Oldsmobile Turbo Jetfire. Today, turbochargers and superchargers can be found in cars from nearly every manufacturer.

Turbochargers and superchargers were designed to enhance engine performance in naturally aspirated engines. Both methods use forced induction to boost an engine’s horsepower. Many people conflate both technologies, but they possess distinct differences. To help you understand, we’ll take a closer look at what these two technologies are and how they differ.

Turbocharge vs Supercharge Engine
Image via Flickr by Don O’Brien | Licensed by CC BY 2.0

What Is Forced Induction?

Forced induction systems work by compressing the air flowing into the combustion chambers of a gasoline engine. The compressed air has a higher density, resulting in an increased level of oxygen forced into the cylinder. 

In turn, this higher level of oxygen requires exponentially more fuel. More fuel results in bigger explosions within the cylinder. The larger the explosion, the greater the power your engine generates. That’s why a 3.0-liter engine typically has lower horsepower-rating than a 5.0-liter engine. It’s all about the amount of fuel burned within the cylinder.

Without forced induction, the density of the air around an engine limits its power output. Therefore, an engine at a higher altitude without forced induction produces less power than an engine running at sea level. The use of turbochargers and superchargers increases power regardless of altitude and ambient air density.

How Does a Turbocharger Work?

Turbochargers (and superchargers) are basically air compressors. Turbochargers do not connect mechanically to the engine. Instead, they use the engine’s exhaust stream to spin a turbine that powers the compressor.

The turbine spun by these exhaust gases passing through it creates a vacuum that compresses the air. Then, the turbine forces it into the engine’s intake manifold. The faster the engine spins, the faster the turbine spins. This exponential increase enables anywhere from 25% to 45% power boost.

Turbochargers do not provide instant power because this exhaust-driven system takes time to spool up. In order to attain optimal boost, the turbine must reach a specific speed, resulting in a momentary lag, often referred to as turbo lag, as the turbocharger works to get up to speed.

Turbochargers use exhaust gases, which helps improve the engine’s efficiency. Also, because turbochargers use a wastegate, they emit less exhaust gas, making them a greener option. In addition, they work extremely well on smaller engines, thus you’ll often find them paired to four-cylinder engines. They also weigh less, which improves fuel economy.

Additional drawbacks to turbochargers include their more complex installation. And unlike superchargers, the turbocharger was engineered to deliver boosts between a specific engine operating range instead of across the entire powerband. Turbochargers also run hotter, requiring a higher engine oil viscosity to compensate for extreme operating temperatures.

How Does a Supercharger Work?

Superchargers use a turbine that mechanically connects to the engine through a chain or belt. The supercharger turbine spins as the engine crankshaft turns, and creates a vacuum that compresses air like the turbocharger. Then, the air gets forced directly into the engine.

Because the supercharger directly connects to the engine crankshaft, it creates a linear powerband. In simple terms, the direct relationship to the crankshaft provides instant power, boosting output between 30% and 50%. You get all that power throughout the powerband and never experience turbo lag.

The linear connection results in more power than turbochargers, but also lowers efficiency. Superchargers draw power from the engine, essentially making the engine work harder. In addition, the supercharger doesn’t use exhaust fumes so there’s no wastegate to limit those raised emissions.

Superchargers provide optimal impact on larger engines with more cylinders and higher displacement. Without the turbo lag, you can access instant power across the entire powerband and achieve significantly more horsepower than with a turbocharger. In addition, superchargers don’t produce as much heat, resulting in a longer lifespan.

Unfortunately, the power draw from the engine lowers the supercharged engine’s economy. Also, the supercharger makes a lot of noise. Only the most avid gearheads find the sound appealing, leaving others to block their ears as you race by.

Which Is Better?

If you’re considering adding a turbocharger or supercharger to your vehicle, both offer an effective way to boost power, though in decidedly different ways, and with different results. If you want to strike a balance between performance and economy, you’re better off with the turbocharger. However, if you need a solution to improve horsepower, whether you live in a high-altitude region or like to race on the weekends, the supercharger produces much better results.

If you’re looking at a new car, truck, or SUV and have to choose a powertrain, understanding the differences between the turbocharger and supercharger will help you make a good decision. You most likely won’t find a supercharger on anything but a sports car or sport-inspired SUV or truck. If you see a supercharger on a four-cylinder engine, the power created could cause mechanical issues with your engine.

If you happen to be looking at a used vehicle, keep in mind the turbocharger wears out faster than a turbocharger. Also, be sure to have a qualified mechanic inspect the forced induction system, especially if the system was installed post-production. The complexity of turbochargers make them difficult to install, and you might encounter a system that wasn’t installed correctly.

At New Jersey State Auto Used Cars, we know every driver values power and efficiency differently. If you’re looking to upgrade your Jersey City commute with a new car, truck, or SUV, New Jersey State Auto Used Cars has an expansive inventory of quality used vehicles with various powertrain options, including turbocharged and supercharged engines.

We invite you to browse our inventory online. When you’re ready for a more personal demonstration, you can stop by our dealership on Sip Avenue at any time. One of our friendly, professional staff will show you the different powertrain options, and even let you take your favorite for a test drive.