Turbocharged engines: the pros and the cons
When dealing with high engine pressure, you run the risk of experiencing ‘pre-ignition’ — which is when raw fuel ignites before the spark plugs can ignite it. Accelerate hard with a turbocharged car and the engine pressures will spike immensely, increasing the chances of pre-ignition. Modern engines come with a knock sensor and software that help to prevent pre-ignition by detecting it and spraying additional fuel into the chamber, contributing to a further reduction in fuel economy.
For this reason, many modern-day turbocharged engines will also take premium gas. Higher octane gas has a greater resistance to pre-ignition, making it well suited for use in small, high-compression turbocharged engines. You can find out which gas is appropriate for your vehicle by checking the owner’s manual, but if it’s a modern-day turbocharged engine, there’s a good chance it takes premium gas.
While many modern-day engines are quite reliable, turbocharged engines do come with some additional componentry in the way of the turbocharger itself, the intercooler and all the piping required to deliver the compressed air to the engine. This could make engine repairs or maintenance more expensive when compared with a traditional naturally aspirated motor, but like reliability, this will vary from vehicle to vehicle. It’s best to research reliability ratings and repairs costs for the turbocharged vehicle you’re looking at, as these figures vary from model to model. You no longer have to worry very much about a turbocharged car being unreliable, though — the technology has come a long way since the 1980s.
To recap, these are the pros and cons of a turbocharged engine:
Pros
More power and torque from a smaller engine
More torque low in the RPM range
Can provide better fuel efficiency when driven very carefully
Cons
Fuel economy can tank when driven aggressively May require premium fuel Can raise repairs costs
Are they reliable? As we briefly touched on above, turbocharged engines are more complicated and have more parts than a non-turbocharged engine. While most modernday turbocharged engines are fairly reliable, the more complicated design can raise repair costs should you experience problems or have a front-end collision. A turbo can also put certain components under intense stresses, which may reduce engine life over time.
“From a standpoint of complexity and the parts, you know, and how much stress some components have, there’s definitely a chance for more things to go bad with these turbocharged engines,” Jake Fisher, director of auto testing at Consumer Reports, told AutoGuide for a report we did on turbocharged engines a few years ago. So while many modern-day turbocharged cars don’t have particularly unreliable engines, you may want to stick with a non-turbo (sometimes call naturally aspirated) vehicle if you want peace of mind that the engine is going to last a very long time. There are more small, turbocharged engines out now than ever, so it’s hard to say whether or not they will last.
We’d research reliability ratings and ownership experiences no matter what car we’re looking at — but be sure to do this if you’re looking at a car with a turbo.
How can I spot a turbo failure? Because the turbocharger is such a critical component, it may be obvious if yours fails. The first sign of a small or minor turbo failure will likely be engine light on your vehicle’s dashboard.
A turbocharger that has failed completely, meanwhile, may make a loud whirring or buzzing noise. You will also experience a loss in power and if your turbocharger is leaking oil, blueish smoke may appear.
Some vehicles are equipped with a ‘boost gauge’ that tells you how much pressure the turbocharger is producing. If the value displayed on the gauge under throttle is less than it usually is at a given RPM, there may be an issue with your turbocharger.
What is a supercharged engine? Both a turbocharger and a supercharger are meant to achieve the same goal: increase engine power by forcing air into your vehicle’s engine.
A turbocharger uses spent exhaust gasses to spin a compressor wheel and deliver compressed air to the engine. A supercharger, however, is attached to your engine’s crankshaft by a belt. The belt spins two screw rotors within the supercharger, which compress air and feed it into the engine. The air escapes through a discharge route on the bottom of the supercharger.
We hope this article answered all the questions and concerns you have regarding turbocharged engines.