Turbochargers for
gasoline vehicles
The concept of turbocharging is fundamentally the same for gasoline and diesel engines. However, there are some differences due to the different combustion processes of the fuels.
In a gasoline engine, the air-to-fuel ratio needed for ignition is very sensitive and needs to be controlled precisely. In a diesel engine, the air to fuel ratio is always “lean” due to the excess of air. The exhaust gas temperatures are therefore generally higher from a gasoline engine than from a diesel engine (~950-1050C°). Thus, the turbocharger for a gasoline engine requires advanced materials to withstand the high thermal loading conditions. Special alloys, including expensive materials such as nickel, are commonly used for these turbochargers.
Turbochargers for
diesel vehicles
Turbochargers have traditionally mainly been applied to diesel vehicles and almost all diesel vehicles in Europe are turbocharged today. The concept of turbocharging is fundamentally the same for gasoline and diesel engines. However, there are some differences due to the different combustion processes of the fuels.
In a diesel engine, while the piston is approaching TDC (top dead center) during the compression stroke, the fuel is injected and combustion happens spontaneously due to the high pressure and high temperature in the combustion chamber. For diesel applications, the engine compression ratio needs to be high in order to initiate combustion.
Gallery
