Are Turbocharged Engines Less Reliable?

By Consumer Reports

September 19, 2021

Turbocharging has become a common way for auto manufacturers to strike a balance between power and fuel economy. The concept is to allow a small engine to work like a bigger one when more power is needed. This is accomplished by forcing more air into the engine during acceleration, enabling it to burn more fuel. But with the increased stress caused by turbocharging, will these cars end up off the roads earlier than their naturally aspirated counterparts? Or will they go the distance due to improved research and development?

“Generally speaking, turbocharging is a great idea. It’s a smaller engine, but you’re still getting a decent amount of power,” says Mike Quincy, autos editor at Consumer Reports. “The idea with a smaller engine, especially a four-cylinder, is that you’re going to get decent fuel economy without giving up power. But it’s not so easy to generalize about reliability for turbocharged engines. You have to look at the powertrain and the model as a whole.”

Turbocharged engines are often paired to 8-, 9-, or 10-speed automatics. Sometimes the weak spot of the powertrain can be the transmission rather than the engine. These transmission problems could give the appearance that the addition of a turbo to a car model hurt reliability, but that might not tell the full story.

Consumer Reports’ reliability surveys have also found that manufacturers with a lot of experience building turbocharged engines—Audi, BMW, Porsche—tend to have more reliable powertrains. But manufacturers new to the turbocharged market and without as much experience designing these engines are still working out the kinks.

The bottom line is that you want to do your research when buying a new car. If there are reliability concerns, make sure you look into the details to understand how that might apply to the specific model you’re considering. CR generally recommends not buying the first year of a new or redesigned car. But engines often carry over from one model generation to the next and might be used in other vehicles. So if you’re concerned about an engine, check its reliability in our ratings and consider if it’s truly all new or perhaps just new to the model you’re considering.

How a Turbo Engine Works

Engines make power by burning a mixture of fuel and air. Turbochargers work by forcing more air into the engine when the driver wants more power. That lets the engine burn more fuel and generate more power. The turbo is essentially a fast-spinning fan driven by exhaust gases. The technology allows a smaller engine to generate the power of a bigger engine but only when it’s needed, without the bigger engine’s greater fuel consumption. The downside is that some turbocharged engines hesitate before the turbo spools up and delivers a surge of power.

Air is pulled into the turbo from outside the car.

The spinning fan blades compress the air and force it into the system.

The air passes through an intercooler, which cools and further compresses the air.

The now denser air mixes with fuel and ignites, producing more power than a same-sized conventional engine.

The exhaust gases exit the engine, spinning the fan blades of the turbo.

The spinning blades power the turbo to push more air into the engine.

How a Turbo Engine Works

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