Saab reinvents the convertible with the 9-X AIR CONCEPT
September 18, 2008 Just over a quarter century ago, Saab showed the first four-seater convertible to the world, creating a new class of luxury automobile. Now it’s set to do it all over again with the 9-X Air concept car and a visually-distinctive newly-designed Canopy Top designed to aerodynamically cocoon the passenger cell. The design incorporates prominent raked rear pillars that curve upwards to mount a flat folding roof – essentially a development of the Targo roof principle – with a separate rear screen located between them. Instead of having a manually detachable roof section, the Saab Canopy top is fully powered in operation and folds away in the storage trunk. With the top down motorists can enjoy open-top motoring free from buffeting, and with the top up the 9-X Air assumes the appearance of a true coupe. Saab has filed a patent on the convertible roof design and hence the 9-X Air provides a glimpse of what a future convertible from Saab could look like.
The clean, sculpted body contours of the 9-X Air give fresh expression to Saab’s Scandinavian-inspired design ethos and its aircraft heritage. The purposeful stance, with minimal overhangs front and rear, is complemented by a single, wraparound window graphic, smooth uncluttered body surfaces and ‘ice block’ lighting themes.
Anthony Lo, Director of Advanced Design at General Europe said of the car: “Like her sister the 9-X BioHybrid, this car is all about efficiency in design and performance. It offers important benefits in weight-saving and packaging as well as giving us the freedom to take convertible design forward.”
The 9-X Air and its hatchback sibling also showcase seamless, wireless connectivity (Bluetooth) with one or multiple nomadic devices (mobile phones, PDAs etc).
Efficiency in Design and Performance
The 9-X Air has been created by a team under Anthony Lo, Director of Advanced Design at General Motors Europe, working in co-operation with the Saab Brand Center in Sweden.
Designed in parallel with the Saab 9-X BioHybrid concept, the 9-X Air shares its distinctive frontal styling, together with its highly efficient powertrain. The small, 1.4-litre Saab BioPower engine combines a series of measures for more responsible performance: engine rightsizing, turbocharging, the use of biofuels and hybrid technology.
Running on E85 fuel (85% bioethanol/ 15% petrol), the engine delivers a sporty 200 hp (147 kW), giving zero to 62 mph acceleration in 8.1 seconds and projected CO2 tailpipe emissions of just 107 g/km over the combined cycle. Compared to normal petrol, the overall environmental impact on a source-to-wheel basis of using E85 is even more beneficial.
The exterior look of the 9-X Air is defined by the prominent C-pillars, or buttresses, that provide the rear mounting for the unique Canopy Top - a powered, flat-folding roof developed from a Targa top principle. This innovation in convertible design, which distinguishes between a folding roof and a complete folding soft-top or hood assembly, is subject to a Saab patent application.
The Canopy Top is in fabric, rather than metal, to save weight and provide more efficient packaging. It is fully automatic in operation and folds neatly in three small sections under a rear tonneau cover in the trunk deck. The rear screen between the buttresses retracts automatically into the underside of the raised tonneau cover to allow stowage of the Canopy Top. The screen then moves back into position to provide a complete glass surround for the cabin in open-top mode.
This ‘surround glass’ feature, together with an active wind deflector on top of the windshield header rail, provides enhanced occupant comfort. It minimizes buffeting, reduces back drafts and eliminates the need for a wind deflector net. Separating the rear screen from the folding top also enables a larger glass area than is feasible with a soft top and integral screen.
In a further break with design convention, the 9-X Air dispenses with a boot lid. Instead, a large storage compartment, big enough to accommodate two golf bags, slides out from underneath the rear light bar. To save weight, it is spring-loaded, without any power assistance, and slides effortlessly on rollers. Revealed underneath the sliding drawer is a separate compartment for stowing smaller items.
Inside, the 9-X Air features innovative developments in its driver-focused cockpit design and the provision of seamless connectivity for personal nomadic devices, both first seen in the 9-X BioHybrid.
The driver information zone encompasses the top of the door moulding as well as the traditional dashboard. It is a fresh execution of Saab’s traditional, driver-focused cockpit layout and dispenses with a central, floor-mounted console. The zone is a flat, arc-shaped surface, within which a row of five display screens is embedded and illuminated in green 3-D graphics, including an ‘infotainment’ screen and control panel in the driver’s door.
In co-operation with Sony Ericsson, the 9-X Air and its hatchback sibling also showcase the potential for seamless, wireless connectivity (Bluetooth) with one or multiple nomadic devices (mobile phones, PDAs etc). The in-car interface enables streaming of data, entertainment and satellite navigation functions, which are transferred automatically to the car while the device remains in the user’s pocket.
The smarter the device, the more functions in the car. The same unit could also be programmed to remotely lock /unlock the car, raise or lower the Canopy Top, and even remotely change in-car pre-sets.
The Air Canopy Top
The Saab 9-X Air redefines the look of a four-seat convertible by exploiting the distinction between a folding roof and a folding soft-top. "With this car we have created an open air experience that is unique, sophisticated and very premium," says Mark Adams, Vice President GME Design. "From the beginning, we wanted to create an open air car that looked great with the windows up, since this is how convertibles are driven most of the time.”
“The roof treatment has allowed us to completely alter the shape of the car,” explains designer Anthony Lo. Lo and his team set out to bring convertible design closer to the looks of an open sports car or a closed coupé, depending on the configuration. They also wanted to improve open-top comfort for passengers. The result is Saab’s unique Canopy Top concept, an alternative to soft-tops or hoods with rear windows that leave the back of the cabin open when stowed.
A ‘stand alone’ rear screen - separate from the soft-top assembly - is located between the 9-X Air’s raked rear pillars. These support the Canopy Top, a development of the ‘Targa’ top principle. But instead of having a manually detachable roof section, the Saab Canopy Top is fully powered in operation and folds away for stowage in the boot. Saab has already filed a patent application for this feature.
“Convertibles are traditionally developed from a sedan body and have a flat, open rear deck when the hood is down,” says Lo, Director of Advanced Design at General Motors Europe.
“The Canopy Top has allowed us to introduce the rear pillars, which completely change the usual appearance of a convertible, giving it a more dynamic, coupé look. The pillars also anchor a complete wraparound glasshouse, which shelters the occupants from buffeting when the car is open.”
The 9-X Air was conceived in parallel with its 9-X BioHybrid sibling and, as a result, it is a design free from compromise or adaptation. The shape of the windshield and frontal styling, for example, was designed to work in both applications. The two cars share a focus on efficiency, with a power train that uses engine rightsizing, turbocharging, biofuel and hybrid technology to deliver sporty performance together with a significantly reduced environmental impact.
Improved efficiency is also a major benefit of the Canopy Top. As there is no rear screen and supporting material to fold away, it is smaller and lighter than a conventional soft-top. That means it takes up less boot space when stowed.
Reduced weight was another consideration and that dictated the choice of fabric instead of metal for the Canopy Top. “It is the best material, as we save about 100 kilos in weight compared to using metal,” explains Lo. “We have chosen the fabric used for the current Saab Convertible. It is extremely durable and provides effective road noise insulation. For good handling and a lower centre of gravity, you also don’t want any extra weight high up. All in all, we thought of quite a few drawbacks, and not so many gains, from going with a metal roof.”
As the 9-X Air was designed alongside the 9-X BioHybrid, the team was also able to keep weight down by minimising the amount of structural reinforcement necessary to compensate for the removal of a fixed roof. The small strengthening members that were required are in aluminium for further weight saving.
With its Canopy Top stowed, the 9-X Air’s ‘surround glass’ cabin offers improved driver and passenger comfort by managing air flow to reduce turbulence and wind buffeting. The rear screen works in tandem with a small wind deflector on the top edge of the windshield header rail. This is actively deployed, rising and falling according to vehicle speed. At the rear, the screen helps prevent back drafts, as the air flow over the car is no longer sucked back in through an open rear deck.
The Canopy Top design also provides another practical benefit. Compared to the ‘stitched in’ screen of a conventional soft-top, the glass area of the 9-X Air’s rear screen is larger, offering the driver a wider field of vision.
In evolving the 9-X Air and its sibling, Lo and his team worked in co-operation with colleagues from the Saab Brand Center in Sweden. This is a cross-functional group tasked with nurturing and developing all the qualities that go into making a Saab a Saab. It is a unique organisation within GM’s global structure, with a unique way of working.
Visually, the 9-X Air carries forward signature features that reflect Saab’s Scandinavian design heritage and its roots in aviation. These include the extended wraparound effect of the windshield and side glazing, the Aero X-inspired frontal styling, the clean body surfaces, ‘ice block’ lighting themes and distinctive 3-D blue/green instrument graphics. Even the raked rear pillars echo the prominent C-pillar line seen in all Saab cars.
“Overall, the 9-X Air maintains our focus on efficiency. We have produced a sporty, innovative design that offers the sort of functional benefits you would expect from a Saab.”
Ultra Efficient Powertrain
The Saab 9-X Air features an ultra efficient powertrain which combines engine rightsizing and turbocharging with the use of bioethanol fuel and hybrid technology to deliver sporty performance with a significantly reduced environmental impact.
Optimised for E85 fuel (85% biothanol/15% petrol), the small, 1.4-litre BioPower turbo engine generates a substantial 200 hp/147 kW on E85 and an even more impressive 280 Nm (207 lb.ft) of torque. With a full flex-fuel capability, it is a rightsizing formula backed by hybrid technology, giving projected fuel consumption on petrol over the combined cycle of just 5.0 l/100 km and 119 g CO2/km. On E85, CO2 emissions are projected to be even lower, at just 107 g/km, with estimated fuel consumption of 6.5 l/100 km.
Mated to a six-speed manual gearbox with an automatic clutch and steering wheel controls, it is a sophisticated powertrain tailored to meet the environmental and energy-saving priorities of modern day motoring.
Saab already leads Europe’s emerging flex-fuel vehicle segment through the sales of its current BioPower models, which produce more power with E85, as well as less CO2 emissions compared to petrol.
The Saab 9-X Air now takes this proven flex-fuel technology further with an engine that fully exploits the high octane benefits of E85 fuel. It uses a higher compression ratio (10.2:1) and turbo boost pressure (up to 1.6 bar) than would be possible with a petrol-only engine. This is because E85 has a higher octane rating (104 RON) than pump petrol (95 RON), which makes it more resistant to harmful pre-detonation, or ‘knocking’, as the fuel/air mixture is compressed in the cylinder.
Running on E85 fuel, this lightweight yet sophisticated BioPower engine delivers the power characteristics of a much larger powerplant. That impressive torque of 280 Nm (207 lb.ft), for example, is available all the way from just 1,750 to 5,000 rpm. It’s another demonstration of Saab’s rightsizing engine strategy – offering exceptional power without the greater weight, size, fuel consumption or emissions of a larger, naturally-aspirated engine.
Whilst optimised for E85, the engine retains a flex-fuel capability and will still run on petrol, although it will not produce as much power. The engine management system is able to adjust the ignition timing and boost pressure to ensure there is no pre-detonation due to the higher compression ratio.
The advanced specification of this engine also includes direct injection (DI), with centrally-located fuel injectors, and continuously variable valve timing (VVT) on both the inlet and exhaust sides. The result is greater low-end torque and further improved fuel consumption.
Next-Generation GM Hybrid System
Fuel consumption and CO2 emissions are reduced yet further by the addition of the next-generation GM Hybrid system, which features a significantly higher power capability to capture more energy and more electric boost than the current GM Hybrid system. An electric motor/generator, belt-driven from the engine’s crankshaft, replaces the conventional alternator. Electrical power is delivered and stored by the compact lithium ion battery pack, located under the rear cargo floor.
At take-off from rest and during overtaking manoeuvres, the electric motor adds accelerative power. It is also used to re-start the engine, supporting the automatic fuel-saving function whenever the car is stationary. To further improve efficiency, the hybrid system enables a longer fuel cut-off during deceleration and braking.
The electric motor also acts as a generator. It can be powered by the engine to charge the battery pack and support vehicle electrical loads. Or it can be used for ‘regenerative braking’ by capturing the vehicle’s kinetic energy when decelerating and storing it in the battery pack. Sophisticated electronics manage AC/DC and all voltage interfaces, including the 12-volt in-car supply.
The combination of GM Hybrid and Saab BioPower technologies has significant synergies. The hybrid system adds accelerative power and, in effect, improves throttle response. This allows further rightsizing of the engine with additional fuel consumption benefits. Engine rightsizing and hybridisation complement each other, the combined benefit being greater than that of the individual technologies.
Apart from saving fuel and energy, responsible performance means ensuring high standards of safety. In addition to a full arsenal of electronic stability and braking systems, the active safety measures also include a Lane Departure Warning (LDW) function. A front-mounted camera scans the road ahead and warning messages are flashed in the driver information display if the car veers across lane markings. The same camera is also used to monitor light sources at night. Small shutters automatically ‘hood’ the high headlamp beam when on-coming traffic is approaching. For additional occupant protection, pop-up roll bars are fitted behind the rear seats.