PARIS – The replacement for Adam Opel’s Zafira multipurpose vehicle likely will use PSA Peugeot Citroen’s new Efficient Modular Platform 2 that could bring a 22% reduction in carbon-dioxide emissions if Opel matches the success PSA hopes to have with its Citroen C4 Picasso using the same architecture.

Lessons learned from PSA’s EMP2 project, which cut 154 lbs. (70 kg) from the platform, could be employed in the joint PSA-Opel development of a new B-segment architecture to underpin models such as the Opel Corsa and Citroen C3. Meanwhile, Opel will use PSA’s current B-segment platform for the next-generation Meriva small MPV.

And in a twist that gives balance to the General Motors-PSA alliance, Opel engineers in Russelsheim will engineer PSA vehicles, such as the Citroen C3 Picasso, on the upcoming new platform.

GM Vice Chairman Steve Girsky and PSA CEO Philippe Varin recently met in Brussels Thursday and held a press conference at the Maison de l'Automobile to provide more details on the projects the auto makers announced in December. A PSA spokesman says the meeting was held in Belgium because it fit both executives’ schedules.

The announcement of shared duties comes just days after PSA reveals details of its EMP2, which it also will use for C- and D-segment cars and light-utility vans.

Using high-strength steel, tailored blanks and 39 ft. (12 m) of laser welding, a 20-member development team has worked to lighten the platform since beginning the project in 2009.

Engineer Yves Bouvier, a leader of the team in the research and development department, says the C4 Picasso that will be manufactured on the EMP2 later this year in Vigo, Spain, will have a total of 308 lbs. (140 kg) less mass.

Because the platform is lighter, other parts in the top hat can be made smaller. Among the innovations is the design of a single engine cradle to handle both 4-cyl. diesel and 3-cyl. gasoline engines.

The EMP2 will underpin half of PSA’s volume and ultimately will be produced in seven plants around the world, Bouvier says.

This year, the Vigo plant will employ the new architecture with the C4 Picasso, and in Sochaux, France, the platform will be used with the Peugeot 308 replacement. Next year, the architecture will be used in China, and from there will be installed at PSA’s plants worldwide.

The platform can be made with five different wheelbases that could add up to 8.7 ins. (22 cm) to the shortest version, and four different track widths. The EMP2 can handle larger wheels and shorter front and rear overhangs, says Bouvier, which should appeal to designers.

While the GM-PSA announcement does not specify whether the new platform will be used by the Zafira replacement, the EMP2 will be PSA’s C-platform by the time the Opel vehicle is ready. That cooperation will result in a new Peugeot cross/utility vehicle replacing the Peugeot 3008.

The 30 g/km CO2 savings that PSA expects from the C4 Picasso will come partly from the weight savings and from the plastic underbody panels that make the EMP2 more aerodynamic.

In addition, PSA counts on improvements in the powertrain, including a new Aisin-sourced automatic transmission and low-friction Michelin tires. A 30 g/km saving is considerable, taking the vehicle from 129 g/km CO2 with the 112-hp 1.6L diesel to 99 g/km.

Girsky and Varin also say the joint-purchasing organization has been approved and will be in operation shortly. A GM executive will lead the transition, and afterward leadership will alternate between the two auto makers. While cooperation on vehicles is very European, the Opel-PSA purchasing organization will have a worldwide focus.

Additionally, the two companies expect to jointly develop PSA’s next-generation EB engine family of small 3-cyl. gasoline engines. Until now, Opel has not had such small engines.

Opel France, like Opel Europe, saw a difficult 2012. In a French market off 13.9%, the brand’s sales slid 23.8%. In a Europe down 5.5%, Opel fell 13%, according to the European Union’s auto makers’ group, the ACEA.

However, thanks to Peugeot’s tumbling deliveries, Opel was the third best-selling brand in Europe last year.

The outlook in 2013 is not promising, with Opel predicting a 4.5% decline in Europe to 1.85 million units and a 2% drop in France. But GM is not giving up on its European brand, says Yves Pasquier-Desvignes, president of Opel France.

Besides supporting Opel’s development of three new vehicles launching this year, GM bought the GMAC finance unit from Ally last year, proof in Opel’s eyes that the parent company sees a future for Russelsheim, where Opel is headquartered.

“We didn’t have a captive finance company in Italy” and some other markets, says Pasquier-Desvignes. “Detroit is investing in Opel” with both money and with managers sent to Russelsheim to help retool the auto maker.

Opel’s three new vehicles this year are not replacements, but additions to the brand: The Mokka small CUV enters a fast-growing European segment; the Adam city car can be ordered with a million different looks; and the Opel Cascada is a sleek coupe-cabriolet halo car.