What is a turbo engine and are they reliable?
As the world’s governments continue to crack down on fuel economy and emissions regulations, small displacement turbocharged engines have started to become more commonplace.
Smaller displacement turbocharged engines can return excellent fuel economy if driven carefully, but are still capable of producing lots of power on paper. For this reason, automakers have begun to use them in order to meet these increasingly strict emissions standards and deliver customers the same levels of engine power as before, or sometimes even higher.
In this article, we’re going to briefly describe to you how a turbocharged engine works and answer common questions consumers have with regards to turbocharged (sometimes called forced induction) engines. Turbo engines can be found in all types of vehicles these days, including trucks and SUVs, so we’re hoping this post will arm you with the knowledge you’ll need when you go shopping for a new or a modern used vehicle.
What is a turbo engine and how does it work? In the simplest of terms, a turbocharger draws in air, compresses it and then feeds the pressurized air into your engine’s intake manifold. This dense, pressurized air then forcefully enters the combustion chamber when the piston makes a downward stroke. With more oxygen entering your engine at a quicker rate, you can burn more fuel. And when you burn more fuel, you make more power.
That’s only one part of the turbocharging process, though. After the combustion cycle has completed, the hot waste gas exits the combustion chamber through an exhaust outlet. As the waste gas exits, it passes through the turbocharger and spins a compressor wheel. As the compressor wheel spins, it draws in cool atmospheric air from the opposite side of the turbo, starting the process over again.
There’s one small issue with this process: air gets hot as you compress it and heat robs your engine of power. The compressed air must be cooled before it enters your intake manifold, then.
To remedy this, the com- pressed air will pass through a heat exchanger, sometimes called an intercooler, on its way to the intake manifold. An “airto-air” intercooler will cool the hot compressed air using the flow of the outside air as you drive along.
There’s also a “water-to-water” intercooler, which uses cold water to cool the compressed air.
Pros and cons The two major advantages of a turbocharged engine are greater power density and increased fuel efficiency.
Because a turbocharger enables a small engine to produce more power, manufacturers can downsize their engine displacement. A smaller engine is typically a bit better on gas than a larger one, which contributes toward some fuel savings.
Turbocharged engines also utilize the engine’s hot, expelled air to spin a compressor wheel and draw in outside air, reducing the amount of waste produced.
For these reasons, a turbocharged engine can be more efficient than a naturally aspirated one when driven carefully.
A turbocharged engine’s efficiency can quickly fall off if you begin to drive aggressively, however. In order for an engine to operate properly and not break down, it must achieve a proper air-fuel mixture ratio in the combustion chamber. A turbo will force more oxygen into the engine, especially under heavy throttle, so the engine will also burn more fuel in such a scenario.
Turbochargers also increase the atmospheric pressure in your engine.