Maybe U.S. automakers think polycarbonate roof systems aren't quite ready for prime time yet, but that doesn't mean that they've given up on experimenting with the material.
Ford Motor Co.'s Lincoln division rolled out a concept with a PC roof for the second year in a row at the North American International Auto Show in Detroit Jan. 12, this time on its Lincoln C, a small-car demonstration project.
``We're looking at lightweight options to reduce fuel economy, and even though it's a small car, we wanted it to still feel light and airy,'' said Greg Hutting, project manager for Ford's Irvine strategic concepts group, during an interview at the C's unveiling.
Concepts are a prime place for the company to grow comfortable with using the material, as well as giving designers some new freedom to flex their imagination, he said.
``It can do more complex forms than you can in glass,'' he said. ``It opens up a lot of avenues.''
On the C concept, the PC roof stretches over the length of the car, flows down to meet with the body panels and incorporates the antenna.
``And while we can't use PC in the windshield because of [federal] regulations, we can still look at new ways to use materials there,'' Hutting said.
Lincoln designers eliminated the standard sun visor in the car's interior by using an electro-chromatic element within the polyvinyl butyral film inner layer between the inner and outer glass panels.
It makes sense to experiment with materials on a luxury-level vehicle because the higher prices of those vehicles make individual part costs less of an issue than it would be in an economy car, Hutting said.
But concepts do not guarantee real-world production. The Lincoln MKT debuted in 2008 as a concept car with a polycarbonate roof. The production version shown at the same time as the C uses glass panels, rather than plastic.
``It gives us a way to allow for the light and open space that designers envisioned,'' said Ford spokesman Mark Schirmer.
Plastics still is finding a new spot on the MKT, however. The crossover vehicle uses a thermoplastic polyolefin as the outer skin on its lift gate as part of a way to lighten that rear panel.
Even if polycarbonate is not on a Ford production vehicle yet, Hutting said, it still gives designers a chance to explore new ideas.
``It affords you more than weight efficiencies,'' he said. ``It opens up a lot of design freedom.''