World’s First Plastic Engine Support For Mercedes GL Class

Plastic is finding more uses into our vehicles, allowing weight savings and better heat management, two aspects contributing to better fuel consumption.

Daimler is now using the world’s first plastic engine support for its six-cylinder diesel engine installed in the new GL Class.

The announcement was made at the VDI-K Conference “Plastics in Automotive Engineering”, held in Mannheim, Germany.

According to BASF, compared to the previous aluminum support, the plastic part offers improved acoustical properties, better thermal insulating characteristics and a definite weight advantage, while being able to withstand the same load.

The part, which supports the engine with the aid of the engine mounts, is molded from Ultramid A3WG10 CR, a highly reinforced specialty polyamide from BASF that has been optimized for high mechanical loads.

Joma-Polytec in Bodelshausen assumed responsibility for designing the injection mold and producing the plastic engine support.

The torque supports that are already used by various automakers in versions of Ultramid transmit only the tilting moment of the engine.

In contrast, engine supports are subject to a permanent load – the engine’s weight – while absorbing in addition the entire engine torque. To date, they have always been made from aluminum.

To replace aluminum in this crash-relevant application, the plastic must fulfill demanding mechanical requirements, While BASF’s Ultramid A3WG10 CR is very rigid, it was necessary to demonstrate that the material exhibited sufficiently low tendency to creep in the confined space of the engine compartment when subjected to a continuous load.

Furthermore, depending on the installation conditions in the engine compartment, the plastic engine support must also withstand high bending moments.

The good acoustic characteristics are the primary benefit of the Ultramid engine support over its aluminum counterpart. Thanks to the damping behavior specific to plastic, the new engine support contributes to a more balanced sound.

An additional benefit is that the heat conduction of the plastic is considerably less than that of aluminum. As a consequence, the Ultramid engine support provides better protection from the engine’s heat for the natural rubber engine mounts connected to it, increasing their service life.

In the context of the CO2 discussion, a weight savings of over 30% for the plastic part versus the aluminum version is seen by both Daimler and BASF as an additional plus.