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Total cost of ownership is requiring further improvements to piston friction reduction as well as additional gains in thermal efficiency. A piston compression height reduction in combination with carbon based piston pin coatings is enabling advancements in both demands. MAHLE implemented a new innovative metal joining technology by using laser welding to generate a cooling gallery. The MonoLite concept offers design flexibility which cannot be matched by any other welding process. Especially an optimum design and position of the cooling gallery as well as durability for very high peak cylinder pressures can be matched. This is particularly advantageous for complex combustion bowl geometries that are needed in modern diesel engines to meet fuel economy and emission requirements. The MonoLite steel piston technology offers a superior compression height reduction potential compared to typical friction welded designs.

In modern car engines, the oscillating masses, the inertia forces of the moving engine parts has to be kept as low as possible. Small oscillating masses are not only the basis for the engine smoothness; they also have a great influence on the reliability and life of the components. The smaller oscillating mass in the crank mechanism minimizes, the weaker the vibrations and reduces friction and wear of the parts. The contribution of the piston pin to the oscillating mass can be between ten and thirty percent. Mass reduction of the piston pin has a corresponding large effect. In the newly developed MAHLE composite piston pin, an aluminum core is pressed in a steel sleeve. This enables a weight reduction in the piston pin up to twenty percent for gasoline engines and up to thirty percent for diesel passenger car engines. As the production of piston pins should be kept simple and economical, the new composite piston pin utilizes a forming process for its manufacturing.