Turbocharger vs. Supercharger: What’s the Difference and Which Is Better?
If you're looking for one of the biggest performance upgrades you can make to an engine, forced induction is usually near the top of the list. By forcing more air into an engine, you can burn more fuel and make significantly more power than the engine could naturally aspirate.
The two most common ways to accomplish this are turbocharging and supercharging.
Both can make serious horsepower. Both can completely transform how a car drives. But the way they create boost—and the way that power feels from behind the wheel—is very different.
So what's actually happening under the hood?
First, What Is Boost?
An engine is essentially a giant air pump.
During the intake stroke, the engine pulls air into the cylinders, mixes it with fuel, compresses that mixture and ignites it. Generally speaking, the more air and fuel you can efficiently burn, the more power the engine can produce.
A naturally aspirated engine relies primarily on atmospheric pressure and the movement of the pistons to fill the cylinders.
A forced-induction engine uses a compressor to force additional air into the engine under pressure.
That pressure is what we commonly refer to as boost.
If you've heard someone say their car is running "15 pounds of boost," they're talking about approximately 15 PSI of pressure above atmospheric pressure in the intake system.
Turbochargers and superchargers both create this pressure. The major difference is what powers the compressor.
How Does a Turbocharger Work?
A turbocharger uses energy from the engine's exhaust gases.
Inside a turbocharger are two primary wheels connected by a common shaft: the turbine wheel and compressor wheel.
Exhaust gases leaving the engine are directed through the turbine housing, spinning the turbine wheel. Because the turbine and compressor are connected by the shaft, the compressor wheel spins along with it.
The compressor then draws in outside air, compresses it and sends it toward the engine.
The basic process:
Exhaust → Turbine → Shaft → Compressor → Boost
One of the biggest advantages of a turbocharger is that it takes advantage of energy in the exhaust stream rather than requiring a direct mechanical drive from the crankshaft.
Modern turbochargers can spin at incredibly high speeds—often well into six-figure RPM ranges.
Why Turbocharged Cars Can Make So Much Power
Turbochargers are extremely effective when you want to dramatically increase an engine's power output.
A properly sized turbo can allow a relatively small engine to produce power levels that would traditionally require a much larger engine.
That's why today you'll find turbochargers on everything from economy cars to high-performance sports cars and race cars.
It also explains why turbocharging has become especially popular in the aftermarket.
Changing things like turbocharger size, boost pressure, fueling, intercooling and engine tuning can dramatically change how much power an engine produces.
But there is a tradeoff.
Turbo Lag
A turbocharger requires sufficient exhaust flow to spin the turbine and compressor.
At lower engine speeds, there may not be enough exhaust energy to immediately produce maximum boost.
Press the accelerator and there can therefore be a short delay before the turbo reaches the speed necessary to produce significant boost.
That's turbo lag.
Once the turbo reaches its effective operating range—or "spools"—the difference can be dramatic.
Anyone who has driven a heavily modified turbocharged car knows the feeling:
Not much happens...
The turbo starts spooling...
And suddenly you're making boost.
Modern turbocharger technology, twin-scroll housings, variable geometry designs and improved engine management have dramatically reduced turbo lag.
But that rush of power is still part of what gives many modified turbocharged cars their personality.
How Does a Supercharger Work?
A supercharger accomplishes essentially the same basic goal:
Compress more air and force it into the engine.
But instead of using exhaust gases, a traditional supercharger is mechanically driven by the engine.
Most commonly, the supercharger is connected to the crankshaft through a belt and pulley system.
As the engine spins, the supercharger spins.
The basic process:
Crankshaft → Belt → Supercharger → Boost
Because the supercharger is directly connected to the engine, boost response can be extremely quick.
Press the accelerator and the supercharger responds essentially immediately.
There's no need to wait for exhaust gases to spool a turbine.
The Supercharger Advantage: Instant Response
Throttle response is one of the biggest reasons enthusiasts love superchargers.
A properly configured supercharged engine can feel like the same engine suddenly gained a lot more displacement.
Rather than waiting for a surge of power higher in the RPM range, additional torque can arrive almost immediately.
That makes superchargers especially fun on larger-displacement engines.
Take a big V8, add a supercharger, and you can get huge torque throughout much of the rev range.
And, of course, there's another benefit enthusiasts appreciate:
Supercharger whine.
The distinctive high-pitched sound from certain supercharger designs has become almost as iconic as turbo spool and blow-off-valve noises.
So Why Doesn't Everyone Use a Supercharger?
The biggest disadvantage is that the supercharger requires power from the engine to operate.
Because it's mechanically connected to the crankshaft, some of the engine's power is being used to spin the supercharger itself.
This is commonly referred to as parasitic loss.
The supercharger may help the engine make considerably more power overall, but some of that output is consumed driving the compressor.
Turbochargers don't have the same direct mechanical load because they're powered by exhaust energy, although turbo systems aren't completely free of losses either.
That's one reason turbochargers can be particularly efficient at producing large amounts of horsepower.
Turbocharger vs. Supercharger
Here's the simplest way to think about the differences:
| Turbocharger | Supercharger | |
|---|---|---|
| Powered by | Exhaust gases | Engine/crankshaft |
| Throttle response | Can have some lag | Usually immediate |
| Efficiency | Generally higher | Generally lower |
| Direct parasitic loss | Lower | Higher |
| Power potential | Extremely high | Extremely high |
| Low-RPM response | Depends on turbo sizing | Usually excellent |
| Sound | Turbo spool / blow-off valve | Supercharger whine |
| Tuning potential | Extremely flexible | Extremely capable |
Neither system automatically makes a car better.
They're simply different ways of accomplishing the same goal:
MORE AIR + MORE FUEL = MORE POWER.
Different Types of Superchargers
Not all superchargers behave the same way.
Three of the most common designs are Roots, twin-screw and centrifugal.
Roots-Type Supercharger
Roots-style superchargers are famous for producing strong boost and torque at relatively low RPM.
They're commonly associated with high-performance V8s and muscle cars.
Their biggest attraction is immediate response.
Hit the throttle and the engine responds.
Twin-Screw Supercharger
A twin-screw supercharger compresses air internally using intermeshing rotors.
They're known for strong efficiency and excellent low-end and midrange performance.
Like a Roots blower, they can deliver the instant torque people typically associate with supercharged engines.
Centrifugal Supercharger
This one gets interesting because a centrifugal supercharger actually shares some similarities with the compressor side of a turbocharger.
Instead of exhaust gases spinning the compressor, however, it's mechanically driven by the engine.
Boost generally increases as engine RPM increases.
As a result, centrifugal superchargers don't necessarily deliver the massive low-RPM torque hit associated with Roots or twin-screw designs.
Instead, power tends to build progressively toward redline.
Turbo Size Changes Everything
Saying "it's turbocharged" doesn't tell you how the car will behave.
Turbocharger sizing plays a huge role.
A smaller turbo generally spools faster and produces boost earlier in the RPM range, giving you better low-end response.
The downside is that a small turbo eventually reaches the limit of how much air it can efficiently move.
A larger turbo can flow substantially more air and support significantly more horsepower.
But that larger turbine and compressor assembly may require more exhaust energy to reach its effective operating speed.
That means boost may arrive later.
This creates one of the classic decisions when building a turbocharged street car:
Response vs. Maximum Horsepower
The biggest turbo isn't necessarily the best turbo.
For a street-driven car, a responsive setup making slightly less peak horsepower can often be much more enjoyable than a giant turbo that doesn't wake up until the upper end of the tachometer.
It's not just about how much power you make. It's about where you make it.
Why Intercoolers Matter
Compressing air creates heat.
And hotter intake air isn't something we want when trying to make reliable horsepower.
That's why many forced-induction systems use an intercooler.
The intercooler's job is to remove heat from the compressed air before it enters the engine.
Cooler air is denser, meaning it contains more oxygen for a given volume. Reducing intake temperatures can also help reduce the likelihood of engine knock or detonation.
Intercoolers can generally be divided into two major categories.
Air-to-Air Intercooler
An air-to-air intercooler uses outside airflow passing through the intercooler core to remove heat from the compressed intake charge.
They're simple, effective and extremely common on turbocharged performance cars.
Air-to-Water Intercooler
An air-to-water system circulates coolant through a heat exchanger to remove heat from the intake charge.
These systems can allow for compact packaging and excellent cooling performance.
Both approaches can be extremely effective when properly designed.
What About Reliability?
This is where the quality of the entire setup matters more than whether the car uses a turbocharger or supercharger.
Forced induction increases cylinder pressure, heat and stress.
That doesn't automatically mean the engine will be unreliable.
Modern factory turbocharged and supercharged engines demonstrate that forced induction can be perfectly suitable for long-term street use.
The important factors include proper engine tuning, adequate fueling, effective charge cooling, proper lubrication, good-quality components, appropriate boost levels, good maintenance and understanding the limits of the engine.
A poorly tuned car running moderate boost can be far more dangerous to an engine than a properly built combination producing considerably more power.
The tune matters.
And when you're modifying a forced-induction vehicle, the supporting modifications matter just as much.
Which One Is Better?
There isn't a universal winner.
If you want immediate throttle response and a strong, predictable torque curve, a supercharger can be an incredible setup.
If you're chasing maximum power, efficiency and tremendous tuning flexibility, a turbocharger is difficult to beat.
Sometimes the decision simply comes down to the personality you want from the car.
Some enthusiasts love the instant torque and whine of a supercharger.
Others live for the sound of a turbocharger spooling followed by the rush of boost.
At BTR, we'll admit we're a little biased.
There is something addictive about hearing a turbo begin to spool, watching the boost gauge climb and feeling the car completely change character as it comes into boost.
It's a major reason turbocharged cars have developed such a passionate enthusiast following—and it's a huge part of the performance world BTR has been involved with for years.
But whether you're Team Turbo or Team Supercharger, both technologies have given us some of the most exciting performance cars ever built.
At the end of the day, we're all chasing the same thing:
More boost. More power. More fun.
Which side are you on—Turbo or Supercharger?
Let us know, and stay tuned to BTR for more performance tech, tuning information, builds and automotive content.