Turbocharger Boost: Why So Many Turbos?
If you've searched for a new car lately, you've probably noticed them: turbocharged engines. Modern vehicles are increasingly offering turbocharged engines in their powertrain lineups. In some cases, these powerplants are even replacing older, nonturbo motors, leaving drivers with no choice but to pick a vehicle with a turbocharger. So what's the reason for all the turbochargers in today's cars?
What Is It?
To understand why so many automakers are turning to turbocharging, it's important to understand what turbocharging is. Simply defined, turbocharging forces extra air into an engine, thereby creating more power. But it's a little more complex than that.
In a "naturally aspirated" car -- that is, one without turbocharging -- air enters the engine using natural forces. This is how most engines were before the recent rise in turbocharged powerplants.
In a turbocharged car, things are different. Air is forced into the engine using a turbocharger. As more air enters the engine, more fuel also enters the engine. That gives turbocharged cars more power than vehicles with naturally aspirated engines.
Of course, you don't need turbocharging to gain power. Automakers could simply enlarge the engine, which would be far easier than fitting a device that pushes air into the motor. So why do so many automakers use turbocharging?
Turbocharged engines offer two main fuel economy benefits. One is that automakers can install smaller engines in cars, because a turbocharged engine can act like a larger engine, providing extra power when drivers need it. But because it's smaller overall, it burns less gas than a bigger powerplant.
The other benefit is that turbochargers aren't active unless drivers request them. In other words, in normal driving turbocharging isn't pushing any extra air on to the engine. That means most drivers end up using less fuel daily, since they're rarely pushing the engine hard enough to activate turbocharging.
Another benefit of turbocharged engines is horsepower. Many modern cars offer turbocharged engines sized between 1.5 and 2.5 liters. But because they feature turbochargers, those engines can make the power of an engine that would normally be twice that size.
So turbocharged cars still offer ample power, but only on demand. When drivers don't need it, they don't have to use it. And in that case, it's fuel economy -- not power -- that sharply increases.
As a result, turbocharged cars give drivers the best of all worlds: They offer the power drivers are used to but the fuel economy they want in a modern vehicle. Turbocharging also helps automakers, which are abiding by increasingly stringent government fuel economy standards.
If turbocharging offers power and fuel economy, why haven't automakers been using it across their lineups for decades?
For one, it's expensive. While turbocharging has been used for years, it's primarily been in sports cars and high-end luxury vehicles. The reason is that it's easier for an automaker to simply enlarge an engine than it is to engineer turbocharging that works well and lasts the life of a car. But with increasing fuel economy rules, automakers are taking on the expense of turbocharging.
Another drawback is reliability. In years past, automakers have stayed away from turbo power because it may not be as durable as natural aspiration. By forcing more air and fuel into a smaller engine, turbocharging can lead to premature wear.
We're not certain that problem has been solved yet. But drivers who buy a turbocharged new car won't have to worry about it for a long time -- and they'll save a lot of money on fuel.