Audi AG, fresh off its launch of the R8 sports car, takes the wraps off another all-new model, the A5/S5 coupe, prior to its formal introduction next week at the Geneva auto show.

The midsize, 4-seat grand tourer is reminiscent of the 2003 Nuvolari concept car and is aimed at expanding the brand’s coupe lineup beyond the TT and 2-door cabriolet variants of the current A4 and S4, expected to be discontinued next year.

Part of the auto maker’s pledge to expand its lineup to 40 models by 2015 through an €11.8 billion ($15.6 billion) product-development investment, the A5 stands as a litmus test for the engineering and design prowess of the Audi brand.

Paired with an all-new A4 sedan, expected to debut later this year as an ’08 model, the two vehicles will square off against BMW AG’s iconic 3-Series sedan and coupe.

“The Audi A5 is the most beautiful car I have ever designed,” says Walter de’Silva, who recently was promoted to head of group design for Volkswagen AG. De’Silva previously served as design chief for the Audi, Lamborghini and SEAT brands prior to Martin Winterkorn’s ascension to chairman of the VW Group, and the new A5/S5 was designed under his watch.

Penned with sleek, flowing lines and an aggressive stance, the A5 is a testament to the auto maker’s melding of engineering acuity and styling grace.

Audi’s gaping single-frame grille dominates the A5’s aggressive maw, with sleek, high-intensity-discharge headlights blending into a distinctive shoulder line that carries over the front and rear haunches before terminating at the wide-set light-emitting diode taillights.

In addition, two pairs of four individual LED daytime running lights, arranged horizontally, reside below the headlights and embody Audi’s fascination with advanced lighting systems.

The body appears clean and sculpted, with a sloping greenhouse and a prominent, trapezoidal C-pillar accenting the taught hindquarters.

A short front overhang also is a prominent design element, as well as a result of better powertrain packaging.

Using an engineering trick adopted from the A8, the A5’s new transaxle positions the front differential ahead of the clutch, thereby improving weight distribution and handling by allowing the powertrain to be mounted further back in the chassis, the auto maker says.

This new Quattro drivetrain arrangement, which features a 40/60 front/rear torque split and torque-vectoring technology, is expected to be adopted by most future Audi models.

Other notables designed for improved road holding and agility include a new rack and pinion steering rack, unique 5-link front suspension with aluminum upper and lower control arms and a revised trapezoidal, multi-link rear suspension.

Although specifics will be detailed after the car’s formal introduction, configurations for European models include FSI gasoline and TDI turbodiesel engines, front- or all-wheel-drive and 6-speed manual, 6-speed automatic and 8-speed continuously variable transmissions.

Audi claims ratings of 170-265 hp for the A5, with DOHC direct-injection gasoline mills including the 1.8L TFSI turbocharged 4-cyl. and the 3.2L FSI V-6. Diesel engines include the 190-hp 2.7L and 240-hp 3.0L V-6s, the auto maker says, noting the 3.0L TDI makes 369 lb.-ft. (500 Nm) of torque and can propel the coupe to 62 mph (100 km/h) in 5.9 seconds.

Combined European fuel economy ranges from 27 mpg (8.7 L/100 km) for the 3.2 FSI to 35 mpg (6.7 L/100 km) with the 2.7L TDI.

North American models likely will feature the larger 2.0L TFSI 4-cyl. and the 3.2L FSI V-6, with the 3.0L TDI likely arriving at a later date if demand warrants.

Inside, the A5’s cockpit is heavily driver-oriented and maintains Audi’s exemplary craftsmanship and attention to detail. Although fresh in its design, the interior is similar to that of the A6 sedan’s, including a well-laid-out center console, teardrop gauge housings and prominent navigation/infotainment screen mounted high on the dash.

Of note is the next-generation Multi-Media Interface system and a new intelligent “comfort” key fob technology, which stores critical vehicle information (mileage, warnings and service updates) for improved servicing at dealerships and has an optional keyless access and ignition feature.

The auto maker also says the A5 is a practical 4-seater, offering sufficient accommodations for two rear seat passengers, along with 16 cu.-ft. (0.45 cu.-m) of trunk space for extended getaways.

Audi has yet to release pricing, but says all A5s will feature 17-in. 5-spoke alloy wheels, automatic climate control, the MMI operating system, a power trunk and the new comfort key as standard when they begin to hit European dealerships in June.

Major options will include adaptive bi-xenon lighting with LED running lamps; keyless access; 3-zone climate control; panaoramic sunroof; video parking assist; DVD navigation; and a 500-watt, 14-speaker Bang & Olufsen sound system.

A distinctive S-line sport package adds 18-in. wheels, sports suspension, new front and rear fascias and more upscale interior trim.

Numerous interior colors, materials and inlays (carbon fiber, wood, piano black) above and beyond those offered as standard are available through Audi’s exclusive Quattro GmbH unit, as well, the auto maker says.

For those wishing for something more aggressive, Audi also is debuting the performance-oriented S5 at Geneva. This is in contrast to the launch of past S and RS models, which the auto maker usually unveils at least one year after the volume model’s introduction.

Donning large 18-in. wheels and tires, along with S-specific front and rear fascias, the S5 exudes a dynamic presence that makes de’ Silva’s elegant lines much more apparent.

Other S-specific traits, such as polished side mirrors, quad exhaust outlets, integrated trunk spoiler and chrome-accented grille, also are present, as are upgraded 4-wheel disc brakes and a new 2-stage electronic stability program.

An improved 4.2L DOHC FSI V-8 producing 354 hp and 325 lb.-ft. (440 Nm) of torque is mated to a 6-speed manual gearbox and Quattro AWD. Audi says the new mill is capable of launching the S5 from 0-62 mph (0-100 km/h) in 5.1 seconds.

For the interior, refinements include sportier seats, steering wheel and gauges, along with various S5 badges and trim options.

Competing with the S5 will be BMW’s all-new M3 coupe, which also is expected to debut in Geneva sporting a new 420-hp 4.0L V-8.

To better match the M3’s newfound power, Audi plans to release a higher-end RS5 model, brandishing the 5.2L FSI V-10 from the S8, at a later date, as well as convertible variants of both A5 models.

msutton@wardsauto.com