Saab is exploring a new go-it-alone platform for its proposed entry-level 9-1 model, managing director Jan-Ake Jonsson told just-auto.

"We want an entry model below the 9-3, but the question is how do you do it," said Jonsson.

GM has a platform that could do the job — the new global Gamma II — developed in Korea by GM-DAT and planned to underpin a family of sub-compact Chevrolet/Daewoo/Opel and Vauxhall models.

But Saab is studying its own alternative for the entry-level model. "It won't necessarily be on the global Gamma," said Jonsson, "that may not have everything that we need, for example, four-wheel drive."

The new 9-1 will likely slot between the Mini and 1-Series from BMW and the A1 and A3 from Audi, the two brands that Saab owners most usually cross-shop before buying a Saab.

An option for the 9-1 is to base it on a shortened version of the new GM Delta 2 platform, which underpins the next-generation Opel/Vauxhall Astra.

The Delta 2 will underpin the next 9-3, due in production around 2012/13 Saab's Trollhatten HQ.

That will boost volume at Trollhatten to a more sustainable long-term level, and make up for the loss of two key new models, the replacement 9-5 and a new compact sport-utility, which will be built outside Sweden.

At this week's Paris Auto Salon, Saab will show a second 9-X concept, the 9-X Air, an open-top convertible, billed as a study for the next-generation 9-3 Convertible, Saab's most iconic design.

At 4,427mm long, 1,826mm wide and sitting on a 2,705mm wheelbase, the 9-X Air is shorter than today's 4.6m long 9-3, but wider by 46mm.

Dimensionally it is very close to an obvious rival, the Volvo S40/V50 series.

This down-sizing of the next-gen 9-3 is a deliberate decision, said Jonsson.

"If we are serious about fuel economy and carbon dioxide, cars can't keep getting bigger and heavier every time they're replaced."

Saab had planned to build the next-generation 9-3 on a modified version of  GM's front-drive Epsilon 2, the basis of the new Opel/Vauxhall Insignia and Saab's range-topping 9-5, but Saab has switched the model to a smaller platform, the new global Delta 2, the underpinning for the new Astra.

"We found that when we engineered the 9-3 off the new premium architecture for the 9-5, we ended-up with two cars that were too similar in size," said Jonsson.

He remains conservative about Saab's future production and sales, which he doesn't forecast to rise above a level of between 150,000 and 175,000 units a year in the near term.

What is coming, though, is a shift in the balance of sales. Currently the 9-3 is worth two-thirds of Saab's volume and the 9-5 one-third.

A new compact SUV, the 9-4X, is due on sale shortly, about a year ahead of the much-needed new 9-5.

The Mexican-built 9-4X will have the major influence on Saab's product line-up, diluting the share of the 9-3 and 9-5.

The five-seat soft-roader, whose architecture is shared with the forthcoming Cadillac BRX, will contribute 22.5% of Saab's total volume.

The bigger, more luxurious new 9-5 will also contribute a smaller percentage of Saab's volume, dropping to the same 22.5% share.

Together they will dilute the significance of the 9-3 to around 55 per cent, said Jonsson.

With the 9-5 switching to Russelsheim and the 9-4X built in Mexico, the decision to switch the 9-3 to the Delta platform throws a life-line to Saab's Trolhatten plant, which will become a global sourcing point for cars off the Delta platform.

Julian Rendell