Before I answer that question, we need to understand what a naturally aspirated engine is? It is an engine that works without a turbo. Such an engine does not need any air-compressing device, such as a turbocharger or supercharger. Which means the engine runs with atmospheric air. The air does not pressure in any form before entering the engine.
A turbocharged engine is an engine that uses either a turbo or supercharger to compress the air before getting to the combustion chamber. Therefore, there is a component that increases the atmospheric air pressure before it gets to the cylinder.
Therefore, 8.2L can be classified as a turbocharged engine and also as a naturally aspirated engine, because some models of 8.2L do not have either a turbo or supercharger; they run with atmospheric air pressure.
Note: The 8.2L naturally aspirated engine has a lower horsepower compared to the one with a turbo.
The highest gross power of 8.2L naturally aspirated is 170 BHP, while the turbocharged 8.2L has about 230 BHP, which means the one with turbo has the highest horsepower due to the availability of turbo.
Therefore, depending on the application, you will determine which one to buy—the one with turbo or without turbo.
However, what is certain is that whether you buy an 8.2L naturally aspirated engine or a turbocharged engine, the fuel efficiency of the engine is never in doubt.
You should also know that there are differences between some components of the engine that are naturally aspirated engines and the one that is turbocharged. For example, the rings are different. That is why if you want to do overhauling while buying the overhauling components, the seller usually asks if it is with turbo or without turbo.
Looking to overhaul or buy parts for your 8.2L Engine, ProDieselParts is the best place to shop parts. Shop turbos for your 8.2L Engine here.