Company Launches New Incremental Business On New HUMMER Model

LAKE FOREST, ILLINOIS, SEPTEMBER 22, 2005 - Tenneco Automotive (NYSE: TEN) today announced several automotive technologies on the HUMMER H3 including the ride control, elastomer and exhaust components.

"We're pleased to showcase our cutting-edge technologies on the new HUMMER H3," said Mark P. Frissora, chairman and CEO, Tenneco Automotive. "Our relationship with General Motors remains strong, and we look forward to providing state-of-the-art engineering and manufacturing capabilities to new vehicle programs such as the H3."

The midsize H3 was designed to achieve extreme off-road performance with comfortable on-road capability, and Tenneco Automotive's monotube shock absorbers, derived from those utilized on GM's full-size trucks, are a key aspect of the H3's chassis system. The monotube design separates the gaseous chamber from the oil, enabling smoother and more precise response.

Tenneco also supplies the exhaust system for the midsize H3, which comprises a catalytic converter assembly, lightweight spun resonator and transverse muffler; all designed for the rugged off-road requirements the H3 demands. The spun resonator features a low-backpressure, lightweight and durable design, and marks the first time GM has incorporated this technology onto one of its vehicle platforms.

In addition, a number of Tenneco's elastomer products are featured on the H3. They include:

• Leaf spring and shackle bushings;
• Front and rear stabilizer bar bushings featuring SLE™ technology;
• Cross member and lower control arm bushings.

These components provide superior NVH performance for everyday road conditions while also increasing ground clearance and wheel articulation needed for off-road performance.

Tenneco is a global supplier to General Motors, providing both ride control and exhaust components for GM passenger cars and light and medium-duty trucks.

Tenneco Automotive is a $4.2 billion manufacturing company with headquarters in Lake Forest, Illinois and approximately 18,400 employees worldwide. Tenneco Automotive is one of the world's largest designers, manufacturers and marketers of emission control and ride control products and systems for the automotive original equipment market and the aftermarket. Tenneco Automotive markets its products principally under the Monroe®, Walker®, Gillet® and Clevite® Elastomer brand names. Among its products are Sensa-Trac® and Monroe Reflex® shocks and struts, Rancho® shock absorbers, Walker® Quiet-Flow® mufflers, Dynomax® performance exhaust products, and Clevite® Elastomer noise, vibration and harshness control components.

This press release contains forward-looking statements. Words such as "expect," "will," "continue" and similar expressions identify forward-looking statements. These forward-looking statements are based on the current expectations of the company (including its subsidiaries). Because these forward-looking statements involve risks and uncertainties, the company's plans, actions and actual results could differ materially. Among the factors that could cause these plans, actions and results to differ materially from current expectations are: (i) changes in automotive manufacturers' production rates and their actual and forecasted requirements for the company's products; (ii) the overall highly competitive nature of the automotive parts industry; (iii) the company's ability to realize the sales represented by its awarded book of business which is based on anticipated pricing for the programs over their lives, and is subject to increases or decreases due to changes in customer requirements, customer and consumer preferences and the number of vehicles actually produced by our customers; (iv) the cyclical nature of automotive production and sales of automobiles; (v) the general political, economic and competitive conditions in markets where the company and its subsidiaries operate; (vi) workforce factors such as strikes or labor interruptions; (vii) material substitutions and increases in the costs of raw materials; (viii) the company's ability to develop and profitably commercialize new products and technologies, and the acceptance of such new products and technologies by the company's customers; and (ix) the timing and occurrence (or non-occurrence) of transactions and events which may be subject to circumstances beyond the control of the company and its subsidiaries. These and other factors are described in more detail in the company's filings with the Securities and Exchange Commission, including in its Annual Report on Form 10-K. The company undertakes no obligation to update any forward-looking statement to reflect events or circumstances after the date of this press release.

CONTACT:
Tenneco Automotive, Media Relations
Jane Ostrander
(1) 847 482 5607
jane.ostrander@tenneco-automotive.com

Tenneco Automotive, Investor Relations
Leslie Hunziker,
847/482-5042
leslie.hunziker@tenneco-automotive.com