Tenneco Automotive to Supply Innovative Electronic Suspension System on New Audi A6

LAKE FOREST, Ill., and BRUSSELS, Belgium, Nov. 17, 2004 -- - Tenneco Automotive announced today that its Continuously Controlled Electronic Suspension -- CES -- will be offered in combination with a four corner air spring system as an option on the A6 and the new A6 Avant as of Spring 2005. Specific market introduction dates may vary.

"Our CES business with Audi demonstrates how Tenneco Automotive's superior technology solutions have fueled our growth," said Mark P. Frissora, chairman and CEO, Tenneco Automotive. "Advanced suspension technologies, such as CES, help our OE customers respond to consumer demand for increasingly sophisticated vehicle content to enhance their driving experience. CES delivers a comfortable ride without sacrificing the safety of sure handling."

Tenneco Automotive's CES is a semi-active suspension system that overrides the trade-off between comfort and handling. It continuously adjusts damping levels according to road conditions and vehicle dynamics, such as speed, turning and cornering as well as driver inputs.

CES uses shock absorbers that include dampers developed by Tenneco Automotive and continuously variable electro-mechanical valves, developed by Ohlins Racing. CES valve adjustments occur very rapidly -- typically within 10 milliseconds -- to produce different damping forces. This adjustment speed provides effective control of wheel resonant vibrations up to 20 Hz. As a result, wheel hop frequency control is achieved in addition to body frequency control.

At the heart of the CES system is an electronic control unit (ECU) that processes driver inputs and data from sensors placed at key locations on the vehicle. The sensors include three accelerometers mounted on the vehicle body and four suspension position sensors, which feed data to the ECU on steering wheel angle, vehicle speed, brake pressure and other chassis control information.

The ECU utilizes control software that processes the sensor information in real time and sends signals that adjust independently the damping level of each shock absorber valve. CES dampers allow a large separation between maximum and minimum damping levels and adjust instantaneously to assure riding comfort and firm, safe vehicle control.

Tenneco Automotive is supplying conventional shocks and struts for the new A6. The company also supplies the Audi A2, A3 and A4.

For the Audi solution, Tenneco Automotive developed the CES damper and algorithm and worked together with Ohlins Racing for the radial valve, Vibracoustic for the air springs and Wabco for software programming. System definition, car integration and tuning work were all done by Audi.

Production for the Audi CES system is at Tenneco Automotive's manufacturing facility in Ermua, Spain.