Next BMW 5-series will be steel

The next BMW 5-series will abandon the part-aluminium construction of the current model in favour of an all-steel chassis when it is launched next year, Autocar has discovered.

The change is being made for reasons of cost and ease of manufacture. The 5-series uses an aluminium space frame front end, bonded and riveted to a steel rear. It was developed to provide better weight distribution and to cut weight.

But a key BMW insider said that the aluminium structure has proved to be too costly and hard to build in large volumes. “It was an expensive solution and troubling to perfect in large-scale production,” he said.

BMW also abandoned plans to provide the new 7-series with an aluminium front end.

The change is evident in the 5-series GT Concept, the executive hatch unveiled at the Geneva motor show that will become a production car later this year. Its structure is all steel.