CARS built in the next decade should be cheaper to run because their bodywork will be made from sheet steel which is 25% lighter than at present. But the next-generation material, which promises an across-the-board economy bonus of 3%,will also boost occupant crash safety protection by being significantly stronger.

This best-of-both-worlds autobody has been announced at the end of a four-year development programme carried out by the engineering services division of Porsche. Costing £14 million, the programme was funded by a global consortium of 35 suppliers, including British Steel. And there seems little doubt that its result - the UltraLight Steel Auto Body (ULSAB) - is set to become the choice material for most of the 52 million cars which roll out of factories each year.

The fact that ULSAB will not add to manufacturing costs will almost certainly guarantee widespread adoption as manufacturers seek lighter structures as part of the drive to create products which emit less CO2. The ULSAB structure is the first step in moves to persuade car makers to make the switch. The size of an upper-medium saloon, the body has been benchmarked for torsion strength and bending against nine current cars which include the BMW 5-series, Ford's Taurus, the Honda Accord and Lexus LS400.