Naturally aspirated engine vs turbo engine. Pros and cons

Today’s cars are equipped with engines that can be cataloged according to several criteria. Depending on the fuel used, either by the number of pistons or the way the air enters the combustion chamber.

If we refer to the way the air intake is done, we can say that we have a naturally aspirated, turbocharged, compressor, or dual induction (turbo and compressor) engines. But which is the best option?

If the first engine ever built was the steam engine, in the late 1700s, the internal combustion engine was invented in the late 1800s. It was on gasoline, naturally aspirated, but a few years later, diesel engines appeared, and in the 1910s also appeared the first engines with forced induction.

Now, a century later, things seem to be quite similar: there are also naturally aspirated engines, but also turbo, as in the beginnings of the car industry, a sign that the world has not really decided on their efficiency … So, which is the optimal choice?

Goodbye mechanical compressor, welcome turbo

We can say without mistaking that, until the 1990s, most cars sold to the general public had naturally aspirated engines. Those with a turbo or a mechanical compressor were usually built for performance, competition, or modified, with manufacturers having very few series models equipped with such engines.

After 1990, there was a small revolution: all diesel engines started to receive a turbocharger and the petrol engines were equipped with a mechanical compressor or turbo.

If in diesel, things were clear and for lower consumption and higher power, the turbo was chosen in unison, in the case of petrol ones, things were not yet established. Petrol engines were still mostly naturally aspirated, followed equally by the turbocharged and mechanically compressed ones.

But, over the years, manufacturers who wanted better performance began to give up on compressors and turn to turbo. Why? Because a compressor was expensive to manufacture, it lacks the engine’s initial power and takes up more space under the hood. Where else do you put that on the consumption and performance side it was inferior to a turbo engine?

And so, easily, engines equipped with a mechanical compressor began to disappear until the 2000s. Only a few brands, such as Mercedes-Benz, Ford, or Range Rover still offered high-capacity supercharged engines. But the number of these models fell to less than 1% of the total number of vehicles sold by 2015.

From diesel to turbo diesel

Also starting with the 90s, the sale of cars on diesel fuel exploded. Why? Because more and more people wanted low consumption regardless of situations, even if they sacrificed performance. So, by the beginning of the 2000s, diesel engines were considered to be underperforming and far below petrol engines. But the public chose the diesel for low consumption, and the manufacturers wanted to improve this product more and more.

What was missing from a naturally aspirated diesel engine? Power. This is how turbo-diesel engines appeared, which date back to the 1930s but began to be popular from 1995 on consumer cars. With the help of a turbocharger, the problem of performance is solved and, suddenly, those who bought a diesel vehicle were enjoying performances equal to those offered by petrol cars but at lower fuel consumption.

Today, no manufacturer offers any naturally-aspirated diesel engines, all are turbocharged. They installed a forced induction system consisting of route, intercooler, turbocharger. Thus, the cars have a small cylindrical capacity, but high power. Even so, diesel engines are slowly disappearing because of their emissions and international laws regarding emissions.

The production of naturally aspirated petrol engines is declining.

Even though the number of naturally aspirated gasoline cars is now the majority, the turbo ones are starting to take over. Why? Because a turbo engine is cheaper to manufacture than one naturally aspirated.

How so? Well, the manufacturers thought of removing a piston from the 4 of an aspirated engine and adding a small turbocharger to the result, with 3 pistons. Less used material, less weight, fewer parts, lower production cost.

As for the new elements, ie the intercooler and the turbine, they are manufactured in huge series, and the cost of manufacture becomes lower than a piston engine with a connecting rod.

Customers have started to use engines with a smaller cylinder capacity of 1 liter, 0.9 or 0.7, because they have lower taxes, pollute less, and consume less. In other words, reducing the number of naturally aspirated engines is a win-win for everyone: the manufacturer sells it more expensive, even if it cheaper to produce, and the customer pays less money in the long run.

Without a doubt, naturally aspirated engines are the most reliable. Because fewer parts are in motion, fewer elements can be damaged, materials are subjected to a lower voltage. Not in vain the most durable engines in the world are aspirated V8s or aspirated diesel, from Chevrolet, Mercedes-Benz or Ford, old engines, of old times. Have you seen a 1 million kilometer turbo engine? You won’t even see it!

If on diesel the situation is clear because you can only choose turbo-diesel engines, at petrol engines you can choose: either turbo or naturally aspirated. Already there are manufacturers that no longer sell naturally aspirated engines, but exclusively supercharged with a turbocharger.

The mass manufacturers, which sell compact and sub-compact cars, have naturally aspirated and turbo engines. 

The advantages of a naturally aspirated engine

  • 1. Cheaper maintenance: Because it has fewer moving parts, but also because the turbo is missing, for a longer period you will spend less money on maintenance. An aspirated engine will not even consume oil like a turbo one. And you don’t have to be careful with starting and heating, as with a turbo.
  • 2. Reliability: in the long run, a naturally aspirated engine is more reliable. The turbo engine is a bit more complicated and if you do not properly maintain the turbocharger, it can leave you when your world is dearer and the repair is not cheap.

The advantages of a turbocharged engine

  • 1. Higher power: Thanks to the turbocharger, a turbo engine has on average about 25-30% more power than an engine of the same type and capacity. And who would not, if they could wish for more power that is welcomed?
  • 2. Lower taxes in some countries
  • 3. Lower consumption: because you have a smaller capacity, but a higher power, you can drive in the city without having to overload the engine, so you will have a decent consumption. On the longer drives, the turbo helps you have a higher power at a lower speed, so you won’t have to drive the engine for much longer. In total, a turbo engine has a lower consumption than one naturally aspirated with the same capacity and significantly lower than one aspirated by the same power. Also, low consumption comes from lower weight.

In a naturally aspirated engine, the air enters without being forced

Disadvantages of naturally aspirated engine

  • 1. Less power than a turbo
  • 2. Higher taxes related to power
  • 3. Increased consumption for the same capacity or power

The disadvantages of the turbo engine

  • 1. More expensive maintenance
  • 2. Low long-term reliability

What type of engine is better? Naturally aspirated or turbo?

Our opinion is that an aspirated engine is better than a turbo, in the case of an everyday car, especially in urban driving and not only. Even if it consumes more fuel, it is better to go to the pump often than often in service.

Or when there are no roads to run, in this situation, the performance factor provided by the turbo does not matter anymore.

We prefer an aspirated engine also in terms of maintenance costs, but also because you can get behind the wheel without waiting for the engine to warm up and you can go directly. If you suddenly accelerate with cold oil or stop it when it is hot in a turbo car, it shortens its turbocharger life.

The best option for a naturally aspirated engine? A small-capacity engine, below 2000 cc, because it resists better in crowded places, heats less like a turbo and does not overload any element under the hood. So, if we were driving mainly in the urban area, we would choose the naturally aspired petrol engine.

But if we were traveling more out of town, I would choose a turbo engine. Consume less, an ideal power gain.

In the end, it all depends on the driver’s preferences, how much he drives, where he drives, and how he drives. 

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