The updated 2015 Audi A8 will get a new set of wheels made from a somewhat unusual material.

Instead of aluminum, the wheels will be made of a plastic composite material called Chromtec.

The wheels' manufacturer, Lacks Wheel Trim Systems, says the wheel comprises "a lightweight structural backbone and a design surface that consists of a proprietary high-impact modified polymer, proprietary urethane cellular foam system and true metallic finishes."

The plastic rims, it says, will have a "true metallic finish," so they should still shine like metal wheels.

What's the advantage of making a wheel out of plastic? As Colin Chapman would say, they "add lightness."

Lacks says the A8's new wheels eliminate 38.8 pounds of weight per vehicle against conventional metal wheels. Removing weight from a car benefits fuel economy, acceleration, and handling--and in a big sedan like the A8, any weight savings is a significant achievement.

Making the wheels lighter could also result in a big reduction in unsprung weight, yielding extra benefits both for handling and ride comfort.

Plastic and composite wheels have been in development for some time.

In 2007, the Fraunhofer-Gesellschaft research facility developed a simulator for testing wheels made from glass-reinforced plastic (GRP).

Six years later, it looks like the technology is finally ready for a production car.

A refreshed version of the current model, the 2015 Audi A8 debuted at last month's Frankfurt Auto Show.

Other updates to the latest A8 include new headlights with Matrix LED tech and sequential turn signals, added electronic safety features like lane assist and night vision, and other tweaks.

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