Four major exhaust system manufacturers disagree on the potential for growth, but each is adopting an expansion plan.
Faurecia and Tenneco will cooperate with engine management firms to seek greater per-vehicle content. Eberspächer hopes to link exhaust systems with its particulate filter and auxiliary heater businesses.
ArvinMeritor and German partner Zeuna Stärker will turn themselves into systems suppliers, hoping to sell automakers an "air-to-air" package that includes fresh-air induction, emission control and exhaust systems.
ArvinMeritor must redefine its exhaust business if it is to grow, said Kurt Tyler, vice president of marketing and new products for the ArvinMeritor Air and Emissions Technologies Group.
"It's a fairly stagnant market and there are no new opportunities for technology, so it's a kind of a zero-sum game," Tyler said.
ArvinMeritor launched an "air-to-air" initiative last year, using its exhaust system expertise to design fresh-air induction systems.
In April, ArvinMeritor bought a minority stake in MTI, a specialist in intake manifold design.
ArvinMeritor's first contract for a complete induction-to-tailpipe system is for the General Motors' SSR platform.
Other exhaust specialists are skeptical about combining air-intake and exhaust systems, but all see a growing connection with engine controls.
The exhaust system "is getting more integrated into the engine management and the powertrain," said Eberspächer CEO Günter Baumann.
Eric Quemere, Faurecia's director of innovation and business development, says particulate filters will need coordination with engine management systems.
"Without the work of carmakers and [engine management specialists] Bosch, Siemens and Delphi, the particulate filter would not exist today," he said.
Faurecia supplied the first particulate trap for the Peugeot 607.
Quemere said as exhaust emission rules become tougher, suppliers must work harder to control particulates and nitrogen oxides.
And he disagrees with Tyler about growth opportunities. With stronger regulations on emissions and vehicle noise, Quemere said "we will see growth in the exhaust business."
Harald Bressler, director of customer teams at Tenneco Automotive's European exhaust systems business, sees only modest growth in exhaust systems.
"Sales in Europe are mainly flat," said Bressler. "Growth is coming from increased material quality and therefore higher material cost."
Tenneco is winning orders for tubular and fabricated manifolds at the expense of cast-iron manifold suppliers, he said.
Eberspächer is trying to combine exhaust systems with its auxiliary heater division and future particulate filter systems to reduce soot in diesel engines.
"We have a great experience in burner systems," said Baumann. Burners are a potential solution to soot building up in filters.
Baumann said low-price diesel exhaust systems were unappealing to Eberspächer.
He said: "With the particulate filters, diesel exhaust systems will become much more interesting and innovative."