Lightweights An intake valve made from silicon nitride weighs in at a mere 26 grams. The corresponding steel valve, on the other hand, weighs 61 grams. This corresponds to a weight saving of around 56 per cent. The fact that the engine would be moving a lighter weight means that the energy gain due to reduced friction in the valve train would be substantial. This achieves a further reduction in weight.
Less friction means improved fuel consumption.
Mercedes engineers estimate that ceramic valves could lead to a consumption improvement of between three and six per cent in a four-cylinder engine. They have also been cooperating with suppliers to continually improve the properties of their materials. 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.