A turbocharger significantly increases an engine's power and efficiency by forcing more air into the combustion chambers. It's a form of forced induction that uses otherwise wasted exhaust gases to spin a turbine, which in turn drives a compressor. This compressor packs more air into the engine, allowing it to burn more fuel and produce more power from a smaller displacement. Essentially, it makes a small engine perform like a much larger one, a concept known as downsizing.
The core benefit is a substantial boost in horsepower and torque without the fuel consumption penalty of a larger, naturally aspirated engine. This is particularly noticeable during acceleration, like when merging onto a highway. For example, a modern 2.0-liter turbocharged four-cylinder engine can easily outperform a older 3.5-liter V6 while delivering better fuel economy in everyday driving.
However, a common experience is turbo lag—a brief delay between pressing the accelerator and feeling the power surge. This occurs because it takes a moment for exhaust pressure to build and spin the turbine up to speed. Modern turbo technology has greatly minimized this lag. When considering a turbocharged car, it's wise to use high-quality synthetic oil and allow the engine to idle for a short period after hard driving before turning it off, as this helps cool the turbocharger's central shaft.
Here’s a comparison of typical power outputs for a 2.0-liter engine with and without a turbocharger:
| Engine Type | Horsepower (HP) | Torque (lb-ft) | 0-60 mph (seconds) | Estimated Combined MPG |
|---|
| Naturally Aspirated | 155 - 170 | 140 - 155 | 8.5 - 9.5 | 28 - 32 |
| Turbocharged | 250 - 300 | 260 - 310 | 5.5 - 6.5 | 24 - 28 |
| High-Performance Turbo | 320 - 350 | 330 - 370 | 4.5 - 5.2 | 22 - 25 |
