Saab's Ethanol-Powered Concept Car

Motoring Channel Staff - 28/Feb/2006

The Saab Aero X concept is a dynamic, two-seater sports coupé that showcases two core brand elements: Saab's aviation heritage and its Scandinavian roots. Here designers Anthony Lo, Alex Daniel and Erik Rokke, who conceived this study at design operations in Sweden, explain its significance.

The muscular shape of the Saab Aero X clearly signals its role as a high performance driver's car, while its looks and visual appeal show this is a design that could only come from Saab.

With innovative features typical of the brand and thrust from a 298kW, twin turbo BioPower engine, it opens up new horizons for Saab's development.

The 2.8-litre twin turbo engine is mounted behind the front axle for an improved centre of gravity and 50:50 weight distribution front to rear, and is fuelled by E100 biofuel, or 100% ethanol.

With variable valve timing and variable geometry turbines for the forced induction system, the engine generates 298kW (400bhp) @ 5000rpm and a stomach churning 500Nm of torque @ 2000rpm. 

The big power comes by way of the direct injection fuel delivery and turbo systems, the latter of which produces a maximum boost pressure of 1.0 bar, or 14.5 psi.

The gearbox is a 7-speed automated manual (which we assume is a twin-clutch idea, like the VW-Audi DSG) and drive for the Aero X concept is delivered to all four wheels.

Weighing 1,500kg, the 7-speed gearbox combines with the ethanol-powered turbo engine to accelerate from 0-100km/h in 4.9 seconds and is electronically limited to a 250km/h top speed. Large 380mm disc brakes are covered by even larger 22- and 23-inch alloy wheels front and rear, shod with tyres with aspect ratios of 265/30 up front and 325/25 at the rear.

The Aero X concept also showcases the potential of Saab BioPower to offer drivers 'green performance': increased engine power with a greater regard for the environment.

Running on 100% bioethanol, a renewable and sustainable fuel, its advanced 2.8V6 BioPower engine delivers impressive power power levels, while continuously variable damping gives excellent real-life driving safety and control.

By combining bioethanol with turbocharging, Saab BioPower exploits the high octane performance of this fuel, as well as its environmental benefits. 

The technology is already well-proven by the outstanding sales success of the Saab 9-5 2.0t BioPower in Sweden and its gradual introduction on other markets.

For the Aero X, Saab takes BioPower to a new level by using pure bioethanol (E100) fuel, with a higher octane rating of 106 RON (almost as high as AV gas) compared to gasoline's 95-98 RON. Using a 12:1 compression ratio and twin turbochargers running at 1.0 bar boost, this high-feature engine delivers an impressive 143bhp/per liter. 

Turbocharging with E100 fuel allows the use of a higher compression ratio - giving more engine power - than is possible with gasoline because of the risk of harmful 'knocking' or pre-detonation. 

"Turbocharging and bioethanol make excellent partners," says Kjell ac Bergström, Executive Director of Saab Automobile Powertrain AB. "In developing this BioPower V6 engine we have been able to take the next step by using E100 fuel, pure 100% bioethanol. That means there are zero fossil CO2 emissions because we are not using any gasoline at all.

"Although the engine is optimized for E100, the engine management system will still make adjustments for any bioethanol/gasoline blend in the tank. So, if there is no bioethanol available, the customer can still use gasoline at any time," says Bergström.

Getting back to the car's exterior design, it is obvious that Saab wanted to make a brash statement with its latest concept. "This car has given us the opportunity to push out the boundaries of Saab design, to explore new directions without any constraint," explains Anthony Lo, GME's Director of Advanced Design.

"It represents our vision of what a high performance car from Saab could look like. In making such a strong statement, it is probably the most self-expressive, emotional design Saab has ever produced.

"We have focused on harnessing the visual potential of Saab's aviation roots, as well as introducing design elements in lighting and instrumentation that have been inspired by our Scandinavian experience."

The car's most striking visual feature - the front-opening glass canopy - combines two themes, aviation and Saab design tradition. While parallels with jet aircraft are obvious, the canopy also 'stretches' a more conventional Saab signature, the wrap-around windshield.

The first Saab 99/900 models introduced this feature, bending the glass screen round at its front corners to meet the A-pillars. The 'cockpit' look is now taken to its extreme on the Aero X, with the A-pillars eliminated altogether. 

The role of this feature as a key Saab 'identifier' is also underlined by the familiar curvature of the top of the screen, where it meets roof section, which echoes the 'peaked cap' look of previous Saabs. "The canopy concept takes the cockpit look to a new level," explains Alex Daniel, principle designer of the exterior.

"It makes a very bold graphic around the car's cabin but it is more than a styling feature. It improves all-round vision for the driver and also makes getting in and out of such a low car rather easier. We remained consistent with Saab and Swedish design principles in giving functionality to this form."

The purity of the exterior design is reflected by the clean surfaces, notable for an absence of 'furniture' such as door handles, rubbing strips or even spoilers. "To maintain the analogy of an aircraft fuselage, the lines had to be kept stretched and smooth flowing, without attracting the eye to any particular point," adds Daniel.

"We wanted to represent the brand's aviation roots in an intelligent way, without using showy gimmicks, which would not be the Saab way."

The aircraft references are there, of course, but presented in a subtle fashion: the deep, front air intake ducts, the 'turbofan' design of the alloy wheels and the further evolution of the front grille with its aircraft-like central motif.

An innovative use of glass with illumination by LED (light emitting diodes) is a recurring theme, both inside and outside the Aero X. "Apart from visualizing the brand's links with aviation, this is the other main theme of the car," explains Erik Rokke, principle designer of the interior.

"The glass industry and the manufacturing of precision instruments is very strong in southern Sweden where we are based. We have seen how glass surfaces are treated to give various optical effects, how light is used with glass and how instrument displays possess a very clear, precise imagery. It was very natural for us to use this as an inspiration on the Aero X," adds Rokke.

The headlamps incorporate single LEDs for full and dipped beam, previewing a development likely on production cars of the near future. These are located behind projector lenses, the details of which are highlighted in daytime running by green downlighting from small LEDs mounted in the top of the headlamp unit.

At the rear, there are no obvious tail-lights at all. Here, a slim, opaque white bar, resembling the body colour, runs across the back of the car. It accommodates LEDs for all rear light functions and when a bulb illuminates its glow is diffused, disguising the pinpoint light source.

In character and performance, the Aero X is the most driver-focused design yet to come from Saab and Anthony Lo views it an important step in helping to define future products for the brand."The future is about looking back, as well as forward, so we can interpret the special qualities that go to make up what a brand stands for," says Lo.

"However, in giving products a clear identity, we should not feel restricted by previous design conventions and the Aero X explores new ways of expressing what Saab stands for. In showing how a focused, high performance sports car from Saab could look, we have been able to introduce a more self-expressive, more assertive design language, tipping the balance away from understatement. The brand's roots in aviation and its rich Swedish heritage are an important part of what makes a Saab a Saab and the Aero X shows how these influences can be presented in a clear and exciting way,"  explains Lo.