Someone in a better position than most automotive industry CEOs to know reckons it will be some time before auto makers adopt the widespread use of lightweight composite materials.

Step forward Alan Mulally, who helped pioneer such technology while leading the commercial aircraft unit of Boeing before taking his current post at Ford. He told Dow Jones there was still plenty of room for improvement in the steel and alloys used to make vehicle frames (chassis) and bodies.

"We cannot make a business case for composites in the auto industry," Mulally said after a keynote address at the Wings Club aviation forum in New York. He added the sheer volume of composites required for mass production in the auto sector and the attendant costs of investing in autoclave ovens to bake the material ruled them out at this stage in the industry's product development cycle.

He said the future of composites in the auto sector lay with thermosets rather than the new breed of thermoplastics that are starting to be adopted by the aerospace sector.