One problem to arise concerned the endurance properties of the ceramic, which is subjected to extreme loads inside the engine. The chances of ceramic valves entering into series production have therefore also increased substantially. The results of bench tests androad tests carried out by Mercedes-Benz to date have also been extremely positive. These tests should clarify the process reliability of valve production, the modifications necessary with regard to engine assembly, and the actual consumption savings in everyday operation. It's fair to say that the moment of truth is approaching for ceramic valves.
Ceramic valves are currently twice as expensive as their steel counterparts.