The project focused on raising the efficiency of gas engines while keeping emissions low, a goal that requires higher combustion pressures and temperatures. These conditions increase mechanical loads on engine components, especially tribologically critical parts such as valve seats, valves, and valve guides. To counteract the resulting wear and oxidation, the work pursued three main technical strategies: the use of advanced, wear‑resistant materials for valve components, the development of thermally stable lubricants, and the optimisation of fuel‑mixing concepts and operating conditions to stay within material limits while meeting future efficiency and emission targets.

In the valve‑guide area, sintered materials with high porosity were employed to store lubricant internally. By pre‑filling the pores with a specially formulated additive, the initial run‑in of the valve stem was improved, leading to a more wear‑resistant and low‑friction tribolayer. Finite‑element simulations of contact pressures and wear volumes for the valve and valve‑seat ring showed that the new material combination reduced the wear coefficient of the valve seat ring by a factor of roughly 10 compared with the reference. The simulations also revealed that the contact pressure distribution remained stable after two hours of operation, indicating good long‑term behaviour.

Lubricant development yielded a family of zinc‑free, viscosity‑reduced oils that achieved friction reductions of 30 % to 40 % in boundary and mixed‑lubrication regimes for the mobile gas‑engine test rig. For the highest‑pressure variant (GEMAN‑15) a 50 % reduction in adhesion friction was measured. These oils also exhibited lower ash content, which is advantageous for downstream exhaust‑aftertreatment systems. The tribological characterisation was performed on a tribometer (TMZ) and the results were corroborated by engine‑level tests on a MAN six‑cylinder engine. In those tests, the new lubricants contributed to a 25 % increase in power output, raising the rated power from 235 kW to 295 kW, while maintaining a peak cylinder pressure of 160 bar and an exhaust temperature below 800 °C. For truck applications, the target life of the cylinder head was raised from 25 000 h to 35 000 h, and the overall engine life target was increased from 800 000 km to 1.5 million km.

The project also addressed fuel‑mixing concepts for hydrogen and its derivatives, ensuring that the new engine concepts remain compatible with future fuel types. The overall system optimisation aligned operating conditions with the material limits identified in the wear and friction studies, thereby ensuring that the increased mechanical efficiency does not compromise reliability.

Collaboration was carried out between automotive manufacturers, research institutes, and lubricant suppliers. The MAN engine manufacturer provided the test platform and operational data, while the research partners supplied the advanced materials and performed the tribological and finite‑element analyses. Lubricant companies contributed the formulation and supply of the new oils for both laboratory and engine testing. The project was funded through a European Union Horizon 2020 programme, with additional support from German federal research agencies. Over its duration, the consortium demonstrated a viable concept for long‑lasting, efficient gas engines, paving the way for future deployments in mobile and stationary applications.