In today’s day and age forced induction engines are becoming the norm. And the two most popular means of forced induction are turbocharging or supercharging. Between the two, turbos are more efficient, and many do believe that superchargers are indeed more reliable.
The focus of the modern-day car industry is efficiency, and carmakers are going to great lengths to develop the most efficient engine possible. This means that reliability is not necessarily the top priority, and turbos do make the engine more complex, which does affect reliability.
A common myth with turbocharged engines is that continuous boosting of the engine shortens the lifespan of the engine. And this is just a myth because a properly implemented turbocharger does not cause any additional harm to the engine no matter what you do.
The main focus is proper implementation, and the modern-day car industry is incredibly sophisticated with state-of-the-art manufacturing and development methods. So no, even though the chances of unreliability are higher compared to a naturally aspirated engine, in reality, modern-day turbocharged engines are reliable.
Benefits of a turbocharged engine
Let’s say you want to achieve 400hp, and the way you would approach this in the older days is most likely to use a larger 8-cylinder engine. The 8-cylinder engine you end up choosing is heavy, fuel-inefficient, and most likely not compliant with modern-day emissions regulations.
On the other hand, you might also opt for a turbocharged 4-cylinder. Some manufacturers like Mercedes manage to push a 2.0L 4-cylinder turbo up to 400hp and 500Nm of torque. And this engine is most likely way more sophisticated and fuel-efficient compared to a good old naturally aspirated V8. From a horsepower and torque perspective, turbocharged engines are amazing.
Your 4-cylinder engine is comparably powerful to a naturally aspirated V8 from a few years ago. But a 4-cylinder also uses less oil, is a lot smaller and lighter. It seems like turbocharging a smaller engine is a great idea, and some manufacturers like Lexus, Honda, Audi, BMW, and Porsche do make really reliable turbocharged engines.
Drawbacks of a turbocharged engine
But turbocharged engines are not perfect, and the car industry tries to mitigate all the drawbacks, with more or less success depending on the problem in question. The main problem for lots of turbocharged engines is the throttle response.
Throttle response is a way of measuring an engine’s response time. And a turbocharged engine has to spoil up its turbos to an optimal level to produce power. Some car manufacturers like Ferrari are known to make turbocharged engines that are as responsive as a naturally aspirated one, but most of the car industry is not.
Another issue is the consistency of the torque curve. As turbocharged cars do not offer a linear power delivery it basically feels like you are driving a 2.0L engine, and then for a second a 5.0 liter, and after the boost ends you are back at a 2.0L engine.
But the main issue is indeed reliability because turbocharged engines do suffer from higher PSI levels which means that they have to be more robust to endure the increased stress levels. The oil in a turbocharged engine is tasked way more than it is in a naturally aspirated engine.
Conclusion about turbocharged engines
Even though it may seem that the drawbacks of a turbocharged engine outweigh the benefits, that’s not true. A turbocharged engine if built well (and lots of them are) is reliable enough. And as the car industry keeps on progressing so do the development and manufacturing processes which further increase reliability.
Forced induction is spread across the entire car industry. From hatchbacks, SUVs, sedans, supercars, and hypercars all the way up to boats and commercial vehicles. With such widespread use, the reliability of a turbocharged engine can not be subpar.
They are not as exciting nor predictable as naturally aspirated engines are, but they are more efficient, lighter, smaller, and more advanced compared to a naturally aspirated engine. And if you consider the amount of fuel you are going to save compared to a naturally aspirated engine, turbos are indeed the way to go.
Is a supercharged engine better than a turbocharged engine?
A supercharged engine is way less efficient compared to a turbocharged engine. This is because a supercharged engine uses the engine itself to produce more power. And as a supercharger spoils up it uses more and more of the power of the engine.
Superchargers are also more expensive compared to a turbocharger, and on a mass-production scale, the price differences are enough to opt for a turbocharger. But they are sometimes more reliable and more exciting, and the experience is up to personal preference.
Is a hybrid engine better than a turbocharged engine?
Hybrids are also becoming more and more popular, and it’s easy to see why. They are indeed the most fuel-efficient and they don’t harm the environment as much. But it is still too early to tell which one of these is better, but as of right now, turbocharged engines do seem like a better idea.
A hybrid is better in city stop-and-go traffic driving, and a turbocharged engine is at its best when driven at constant highway speeds. If you pair modern-day fuel-saving technologies like cylinder deactivation systems, a turbocharged engine seems superior.
Single turbo vs a twin-turbo setup?
Twin-turbo setups are more popular on higher performance vehicles as they usually offer even more power, and there are a few different ways one can develop a twin-turbo engine. Some twin-turbo engines use one turbo to compress the air and force it in the other turbocharger for maximum power.
Modern-day twin-turbocharged engines which keep the turbos inside the V of the engine are the ones that offer the best throttle response because the turbos are almost always spoiled up. A single turbo builds boost slower, which means that the lag is more noticeable. The gas-flow efficiency of a twin-turbo is also superior to a single turbo setup.