Detroit 2008: Saab 9-4X BioPower Concept


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Several months ago word started circulating that Saab was working on a new crossover that would share a platform with a similar vehicle from Cadillac. We still haven't seen the Cadillac but spy photos of a mule with a Chevy Trailblazer body shell and Saab 9-7x front clip combined with a shortened wheelbase have been seen on several occasions. Now just in time for the North American International Auto Show we have the Saab 9-4x BioPower concept.

As the name implies, this new crossover is propelled by one of Saab's BioPower flex-fuel engines. Ethanol has been gaining in popularity as a motor fuel in Saab's home country of Sweden and the GM division has been pushing it hard. Both the 9-3 and 9-5 are available in BioPower editions which is Saab's way of saying flex-fuel power-trains. The 9-4X concept is an all-wheel-drive CUV that gets motivation from a 2.0L turbocharged four cylinder and we've got the full story after the jump.

[Source: Saab]

Saab's first SUV, the 9-7X, is a U.S.-built adaptation of the GMT360 platform that also underpins the Chevy Trailblazer and an assortment of other GM-branded vehicles. The 9-4X moves down in size to an all-new CUV platform that it will share with the upcoming production version of the Cadillac Provoq Concept. platform derived from the GMT319 "Theta" that is the basis for the Saturn Vue/Opel Antara. The 9-4X is powered by a 2.0L turbo four cylinder that's been optimized for use with E85.

The 9-4X engine is an example of what Saab is calling "right-sizing" that we've already been seeing from companies like Volkswagen with their TSI engines and most other manufacturers will be implementing in the next few years. This engine uses a smaller displacement combined with technologies like direct injection, variable valve timing and turbocharging to achieve improved efficiency without sacrificing performance.

The new engine has an aluminum cylinder block and head to help contribute to the vehicle weight reductions that will be increasingly necessary as demands for improved fuel economy accelerate. In the cylinder head, the phasing of both the intake and exhaust camshafts is continuously variable. The fuel is now delivered right to the combustion chambers via a direct injection system. The control of the cams is coordinated with the control of the turbocharger boost and the fuel system to get the most of whatever fuel is used.

Part of optimizing the engine for E85 was taking advantage of the 104 (RON) octane rating of the biofuel by using a higher 10.5:1 compression ratio. A gasoline-optimized version would only run 9.2:1 in order to prevent the pre-ignition that would terminally damage the engine with a 91-94 octane premium petro-fuel. Running on E85, the engine produces 300 hp and 295 lb-ft of torque everywhere from 2,600 to 5,100 rpm.

The electronic controls are used to optimize the combination of valve timing, fuel delivery and turbocharger boost to achieve the wide flat torque curve that is necessary for good all around drivablity. The use of turbocharging and the higher compression ratio allows the engine to overcome the lower energy density of ethanol compared to gasoline. The result is better low end torque than would be achieved by an engine that had been optimized for gasoline and better overall efficiency when running on ethanol. If the tank is filled up with gasoline instead of E85, the engine management system cuts back the boost, adjusts the valve timing and reduces the fuel flow to prevent damage and optimize efficiency.

Once the engine produces all that power and torque it has to be transferred to the road in order to move the vehicle. The electronically-controlled automatic transmission adjusts the shift points when the Sport mode has been selected for better performance. Downstream of that the torque vectoring XWD all-wheel-drive system from the 2008 Saab 9-3 distributes the drive forces to the wheels. Torque distribution is optimized not just for grip but also for handling and stability.

The XWD system can intervene before the electronic stability control has to activate brakes at the wheels resulting in less heating of the brakes and less wear. Torque can be transferred both between the front and rear axles and across the rear axle to the wheels to help it turn in better and follow the drivers steering input better. If the vehicle is understeering, a standard ESC system would cut engine power and apply brake force to the inside front wheel to help the vehicle turn. Torque vectoring systems like XWD can transfer drive torque to the outside rear wheel if there is enough grip to apply a turning force on the vehicle. Acura has a similar system that they call Super Handling-All Wheel Drive and it works remarkably well. A production version of the 9-4X should appear in the next couple of years and is expected to be built in Mexico along with the Saturn Vue and a new Cadillac-badged crossover.



INNOVATIVE 9-4X BIOPOWER CROSSOVER CONCEPT
SIGNALS SAAB PRODUCT EXPANSION

DETROIT – The Saab 9-4X BioPower Concept, revealed today at the North American International Auto Show, confirms Saab's plans to enter the growing crossover segment with a dynamic, driver-focused vehicle inspired by Scandinavian design values and respect for the environment.

The concept's progressive design features are combined with a responsible, fun-to-drive appeal based on BioPower engine technology and a cutting-edge all-wheel-drive system.

"This concept is a clear statement of what our brand is about," said Jan Åke Jonsson, Saab Automobile Managing Director. "It is also an important next step in our plans to enter new market segments with distinctive product offerings."

The design of the Saab 9-4X BioPower Concept reflects a Scandinavian principle of simplicity of form, with clean and uncluttered lines, free of any cladding, moldings or roof bars, and defining "ice-block" surface and lighting themes. The progressive frontal styling and interior design elements also draw inspiration from Saab's widely acclaimed Aero X concept. Innovative load-carrying solutions include a unique ski equipment stowage system, developed with mountain sports specialists Salomon. (Please see accompanying Salomon release.)

Optimized for bioethanol (E85) fuel, t he four-cylinder, 2.0-liter BioPower turbo engine demonstrates Saab's commitment to "rightsizing" – achieving sufficient levels of performance with a smaller, more efficient engine – by delivering 300 horsepower (221 kW) and strong torque of 295 lb.-ft (400 Nm), together with substantially reduced CO 2 emissions on a source-to-wheel basis. (Please see accompanying Powertrain release). The key enabler for rightsizing is turbocharging technology, which Saab pioneered 30 years ago.

Mated to the industry-leading Saab XWD ("cross-wheel-drive") system, this advanced powertrain promises to make driving to a destination as enjoyable as the adventure itself.

The Saab 9-4X BioPower Concept was developed by a team headed by Anthony Lo, GM Europe's Director of Advanced Design, in cooperation with designers and engineers from the Saab Brand Center in Sweden. "We focused on incorporating design themes from the Aero X in a crossover execution, adding functional, lifestyle features to support the activities of customers using this type of vehicle," Lo said.

The driver-focused cockpit in the sporty, four-seater cabin features an Aero X-inspired "clear zone," with a flush-mounted starter button and infotainment controls, that sweeps up from the central console to the main display screen. Signature green lighting is used for all instrument illumination, while other subtle references to Saab's aviation heritage include the "altimeter" speed read-out scale and aircraft-shaped trim on the steering wheel. The panoramic glass roof is in harmony with a car designed to deliver the enjoyment of outdoor pursuits.

Saab designers worked with top Saab Salomon Big Mountain skiers to devise an innovative storage system for stowing skis and equipment inside the car. The rear cargo deck features a sliding floor with a fold-out aluminum ski holder, through which up to three pairs of skis and poles can be slotted. Boots are stowed in an underfloor, heated compartment and, for maximum practicality, the entire rear cargo area is covered in a waterproof and scratch-resistant rubber skin.

The compact, all-aluminum, four-cylinder BioPower engine combines the benefits of turbocharging, direct injection and variable valve timing for the first time with high-octane E85 fuel (85 percent ethanol and 15 percent gasoline). It's a green, rightsizing formula that gives strong power (300 horsepower [221 kW] and 295 lb.-ft. [400 Nm] of torque without the additional weight, size, fuel consumption and higher emissions of a larger, naturally aspirated engine offering similar performance.

Driver involvement is taken to a new level by the innovative all-wheel-drive system, Saab XWD, already available in the 9-3 range. Active management splits torque delivery between both the axles and the rear wheels, via an electronically controlled rear limited-slip differential (eLSD). This responsive system rewards the driver by giving an enhanced, "positive force" chassis balance. Overall, the Saab 9-4X BioPower Concept is a vivid demonstration of Saab's commitment to customers with outdoor leisure interests who seek a sporty driving experience that is in harmony with nature.


Saab 9-4X Concept: Technical Specifications

BioPower engine

1998 cc; four cylinders; 86.0 / 86.0 mm bore / stroke; aluminum cylinder head and block; DOHC, chain-driven. four valves per cylinder; twin counter-rotating balancer shafts; forged steel crankshaft; steel connecting rods; aluminum pistons; oil spray cooled; direct injection; VVT; inlet and exhaust sodium-filled exhaust valves; Saab engine management system; twin-scroll turbocharger; intercooled

BioPower engine data

* Max. boost pressure at maximum torque: 1.2 bar
* Compression ratio: 10.5: 1
* Max power (E85): 300 hp (221kW) @ 5400 rpm.
* Max. torque (E85): 400Nm (295 lb.-ft) @ 2600-5100 rpm
* Max power (gasoline): 245 hp (180 kW) @ 5300 rpm
* Max. torque (gasoline): 353 Nm (261 lb.-ft.) @ 2500- 5250 rpm
* Fuel consumption (combined): 10.5L /100km (22.4 mpg) on gasoline

Transmission

* Saab XWD ("cross wheel drive") all-wheel-drive system, electronic rear limited-slip differential (eLSD)
* Six-speed automatic transmission, steering wheel controls

Suspension

* Front: MacPherson struts, aluminum control arm and knuckle, anti-roll bar
* Rear: Multi-link, aluminum H-arm and knuckle, anti-roll bar

Steering

* Rack and pinion, hydraulic power assistance

Wheels, tires

* 21inch, 245/55R21

Brakes

* Hydraulic, dual circuit, vacuum booster
* Discs front / rear: 378 mm / 378 mm (all ventilated)

Performance data (preliminary)

* 0 - 100 kph: 8.0 sec
* 0 – 60 mph: 7.9 sec
* Top speed: 235 kph ( 146 mph)
* O 2 51 g / km (gasoline)

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