Before buying a car, drivers often consider the differences in the types of fuel used. However, whether an engine is naturally aspirated or turbocharged is an issue that should be taken into account when making a decision. Today, the automotive industry does not produce naturally aspirated engines as often as before; instead, it creates an alternative to naturally aspirated engines by producing cars with turbo engines. There are certain reasons behind this preference of the manufacturers. The first reason for the transition to turbo engines is to reach the legal limits of fuel economy and emission values determined by governments. In this way, cars with turbo engines can easily pass emission and fuel consumption tests. Now let’s look for the answer to the question of what are the differences between atmospheric and turbo engines, starting from the working principles of these engines.
How does a naturally aspirated engine work?
Atmospheric engines take the air pressure needed to burn fuel directly from outside. Unlike turbos, this type of engine operating with atmospheric pressure does not have an extra system that increases the pressure. This means that the engine cannot exceed atmospheric pressure. For this reason, the power output in naturally aspirated engines is more limited than in turbo engines.
In order to avoid this limited power output in naturally aspirated engines, it is necessary to design the engine larger. Therefore, these engines have a weight disadvantage compared to turbo engines. However, naturally aspirated engines respond faster because they do not benefit from exhaust gas like turbos. The gradual process that turbo engines undergo while running causes a short delay in engine response. Because of this delay, called turbo-lag, atmospheric engines are preferred in some sports vehicles.
How does a turbo engine work?
The power and torque produced in motor vehicles are directly proportional to the amount of fuel going into the cylinder. But fuel alone doesn’t make any sense. In order to burn fuel, a certain air flow needs to be made to the engine. This makes airflow one of the most critical issues, which seriously affects engine performance.
The turbo engine has two fan-like components mounted on a common shaft. One of them is the turbine connected to the exhaust, and the other is the air pump connected to the engine inlet. The turbines use the exhaust air from the exhaust to rotate the air pump on the other side of the shaft. The air pump, which normally returns with the air pressure it receives from the atmosphere, turns more when the pressure from the exhaust is added to it. In this way, it can compress a higher amount of air. Compressed high-pressure air is sent to the cylinder after the intake manifold, causing an explosion. This high amount of air sent to the engine mixes with the fuel, resulting in a higher power output.
Advantages of the naturally aspirated engine
Although naturally aspirated engines have some shortcomings over turbo engines, they still have many advantages:
- It is easier to maintain and repair than turbos.
- It has low development and production costs.
- It is somewhat more reliable because some of its components work independently of each other.
- Since there is no turbo lag, it provides direct throttle response.
- The overheating potential is lower than turbos.
Advantages of turbo engine
The word turbo, which is associated with fast and sports cars, does justice to this ascription and has other advantages:
- A car with a turbo engine offers a performance much higher than the horsepower provided by natural air pressure.
- Turbo engines consume less fuel because they are smaller. In other words, the power produced by an atmospheric engine with six cylinders can be produced by turbo engines with four cylinders. This means a fuel saving of close to 20 percent.
- Since less fuel causes less emissions, turbo engines have a more environmentally friendly structure.
- The turbo engine runs quieter than a naturally aspirated engine that produces the same amount of power.
- Since the air pressure is low at high altitudes, turbo engines perform better than atmospheric engines due to their working principle.