* Diesel's lower volumetric efficiency: Diesel engines inherently have lower volumetric efficiency compared to gasoline engines. This means they take in less air per cycle. A turbocharger forces more air into the cylinders, significantly increasing the amount of fuel that can be burned and thus the power output.
* Improved fuel efficiency: While increasing power is a primary goal, the increased efficiency from a turbocharger can lead to better fuel economy. By more completely using the air in the cylinders, the engine extracts more energy from each unit of fuel.
* Reduced emissions: Improved combustion efficiency due to turbocharging can contribute to lower emissions of particulate matter (soot) and nitrogen oxides (NOx). However, it's important to note that sophisticated emission control systems are typically required in conjunction with turbocharging to meet modern emission standards.
* Smaller engine size: A turbocharged diesel engine can achieve the same power output as a larger, naturally aspirated engine. This allows for the use of a smaller, lighter engine which can improve fuel efficiency and vehicle weight, among other advantages.
In short, while increasing power is a key driver, turbocharging diesel engines offers a combination of benefits that make it almost ubiquitous in modern applications, especially in heavy-duty vehicles and some passenger cars.
