The automotive market is in continuous evolution and always more demanding.
So in addition to the usual requirements of style, comfort, handling and powertrain, in the last years the car manufacturers had to take in consideration also new aspects such as safety, economy during usage and all the environmental issues.
Specifically type and quantity of emissions plus oil consumption have become one of the most important aspects to fulfill.
Type of emissions meant a decrease or elimination of the “bad particles” emitted by the vehicles; the target was achieved with the continuous evolutions of the engines through the new “Euro” versions developed during the last years.
Quantity of emissions and oil consumption are directly linked with weight reduction of the vehicles. So, apart of the introduction of better materials in the Body in White (advanced high strength steels and aluminum), this means new developments in the powertrain area. The most important is the downsizing of the engines guaranteeing the same performances.
This could be only possible with a new and more evolved engines design, that of course has to include also new and better materials usage. The parts initially involved in this materials' change are the engine block, the turbine housing and the turbo/exhaust manifolds.
The engine block represents the simplest example of weight reduction for powertrain; passing from cast iron to aluminum means a weight reduction of approximately 50%. Of course also the costs aspects have to be taken in consideration.
In order to guarantee the same performances, the downsizing brought to more powerful turbo charged solutions. So the gas temperatures are increased and consequently the materials of the turbine housing and the turbo/exhaust manifolds have to be changed.