derfA8L

Here's the info from Motor Authority. Wonder how they'll hold up against NYC potholes?

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.

HouTexAudi

I wonder if they can be repaired from road rash like metal wheels? For about $150 you can make a banged up wheel look like new.

derfA8L

I'm wondering if tires can be mounted on them using existing equipment. Would hate to have a blowout far from an Audi dealer in the boondocks and not be able to replace the tire if the local tire place can't cope with the polymer wheel. Could be an issue for early adopters.

cal333

I wonder if the switch to polymer rims is Audi's way of dealing with front suspension noise transmission into the cabin?

Lazydog

I hope not. I would prefer they deal with that in another way. My reasoning is simple. Most Wheels on our cars are nice but aftermarket really out shine OEM. Now if they figured they fixed the problem with a wheel change and you buy aftermarket the issue is still there.

jetinder

Check out the latest encounter technology magazine ... Talks about it there

https://www.audi-mediaservices.com/p...mod-all,pid-1/

On the new car the aluminum based wheels are only about £400 more than standard wheels on an A8 sport in the UK.

cal333

The technology review of the composite polymer wheel would indicate that this acts as a giant vibration damper...which should absorb the transmission of noise from the tire through the suspension into the A8 cabin - check out this website for info: http://www.imiproducts.com/index.php...ts/equal/faqs/

Lazydog

You seemed to have missed my point. While this option is good for Audi it isn't good for someone wanting to replace OEM wheels with aftermarket wheels as the sound will still be transferred.

cal333

You are very correct - aftermarket wheels (at least the expensive ones) are usually machined to extreme tolerances and are put through testing that eventually destroys them - the benefits of well engineered aftermarket wheels are style, optional widths and personalization - if Audi is installing polymer product wheels on the 2015 A8 (complete with plastic chrome cladding) the benefit is not style but functionality - if aluminum wheels are transferring suspension noise into the A8 chassis then the new polymer wheels should eliminate most, if not all, of this racket - as you surmise, changing to aftermarket aluminum wheel will make little, if any difference, in noise transmission - when I switched to 19" rim with a taller sidewall (from the Audi 20" rim) a good part of the sharp noise abated - there is still more tire noise transmission through the suspension into the A8 cabin than I feel acceptable for a quasi-luxury car - hopefully, Audi has discovered that polymer wheels function as vibration dampers and eliminate the bulk of front suspension noise

cal333

Here is another article about the carbon fiber wheels being developed to retrofit high performance sports cars such as the Porsche 911 series - projected cost $15,000!

The net benefit to automotive enthusiasts (or chassis engineers) is that you have a 40- to 50-percent reduction in unsprung mass—which can yield lighter, shaper steering, better handling, and even better acceleration, while reducing noise, vibration, and road harshness. They allow some natural damping from the material itself, which is what helps them achieve impressive gains in the 9-20 Hz 'secondary ride' frequencies that are especially troublesome for chassis engineers to tune out.