First Look: Audi RS 5

Unbridled power lurking in a classically elegant coupé: the Audi RS 5 will debut at the Geneva Auto Show. The high-revving 4.2-liter V8 with its 331 kW (450 hp) unleashes powerful performance while achieving remarkable fuel economy. The seven-speed S tronic and an innovative center differential in the quattro drivetrain transmit power to all four wheels.

A close relative of the V10 which powers the high-performance R8 sports car, the high-revving V8 engine delivers its output from a displacement of 4,163 cm3. Like nearly every Audi gasoline engine, this one also operates via direct fuel injection known by the abbreviation FSI. This same technology has propelled the Audi R8 racing car to four triumphs at the classic endurance race in Le Mans. The common-rail system generates up to 120 bars of pressure.

Intensive fine-tuning of the dual-branch intake and exhaust system allows the undersquare engine to breathe freely; four adjustable camshafts and tumble flaps in the intake manifold facilitate mixture formation. The 4.2 FSI provides imposing torque and is right at home even at high revs – almost like a race engine. The engine delivers 331 kW (450 hp) at 8,250 rpm and – between 4,000 and 6,000 rpm - transmits a maximum of 430 Nm (317.15 lb-ft) of torque.

The vigorous strength, the spontaneous responsiveness, the joyful high-revving, and the throaty, sonorous music: this V8 produced by hand at Audi stunningly combines the essence of power and emotion. The 4.2 FSI propels the coupé’s 1,725 kilograms (3,802.97 pounds) in 4.6 seconds from 0 to 100 km/h (0 to 62.14 mph) to an electronically governed top speed of 250 km/h (155.34 mph). Audi can increase that to 280 km/h (173.98 mph) upon request.

The ultra-powerful eight-cylinder engine averages 10.8 liters of fuel per 100 kilometers (21.78 miles US mpg) - far less than its main competitors. This impressive figure is due in part to the technologies from the Audi modular efficiency platform. The engine and the entire drivetrain have been optimized to minimize friction, the oil pump operates on demand, and an energy-recovery system conserves energy during coasting and braking.

The standard seven-speed S tronic in the RS 5 – with its high efficiency ratio and its high-geared top speed – also enhances efficiency. It consists of two clutches and two subsidiary transmissions. Both subsidiary transmissions are continuously active, but only one is powered at any given time by the engine. Gears are alternately shifted by the two clutches – at lightning speed, smoothly, and almost imperceptibly.

The seven-speed S tronic, which was specially reinforced to accommodate the high-revving V8, can operate in fully automatic mode – or the driver can shift via the innovative selector lever or shift paddles on the steering wheel. By means of the standard Audi drive select, the driver can switch in automatic mode among three different options: auto, comfort, and dynamic. In the launch control program, the seven-speed S tronic ensures flawless acceleration from a standstill – at full power and with minimal tire slip.

Like all RS models, the RS 5 also applies its power to the road with quattro permanent all-wheel drive. As for the center differential, which regulates power distribution between the front and rear axles, Audi – the leading all-wheel-drive brand – unveils the next generation: a crown-gear differential.

The self-locking crown-gear center differential is compact and lightweight – and attains a high efficiency ratio.

Thanks to its package of plates, the differential can widely vary the distribution of torque between the front and rear axles. If necessary, up to 70 percent can flow to the front or as much as 85 percent toward the tail end. The 40:60 ratio of the standard rear-biased configuration ensures sporty handling.

This new differential operates in conjunction with electronic torque vectoring, which affects all four wheels. If one of the inside wheels becomes imbalanced while the vehicle is at its operational limits, then the system slightly decelerates the wheel to obviate wheel spin. This results in terrific traction on the one hand while generating a yaw moment which aids cornering.

The brake system employs powerful and internally ventilated discs, which measure 365 millimeters (14.37 inches) in diameter at the front axle. In order to maximize the dissipation of heat, the steel friction rings are perforated and connected by pins to the aluminum brake discs. The high-gloss black brake calipers bearing RS logos are likewise made of aluminum; the front calipers are fitted with eight pistons each. Audi can optionally fit the front axle with ceramic carbon-fiber brake discs measuring 380 millimeters (14.96 inches) in diameter. They are extremely lightweight, strong, and durable. The electronic stabilization program (ESP) integrates a sport mode and can be switched off entirely.

The speed-dependent servotronic steering in the RS 5 is especially taut. The standard Audi drive select (a vehicle-dynamics control system) allows the driver to switch among three modes of operation – comfort, auto, and dynamic – to adjust steering, the seven-speed S tronic, the sport differential, the engine, and the exhaust system. And if the car is equipped with the MMI navigation system, a fourth mode allows the driver to customize their own profile.

As regards the engine, Audi drive select controls the exhaust system’s two throttle valves and the sound flaps; when they open, the rich sound becomes even more resonant. Along with the sport differential, dynamic steering is another optional component of Audi drive select. Dynamic steering adjusts the steering ratio to a vehicle’s speed – directly for maneuvering at low speeds and indirectly for traveling at highway speeds. At the vehicle’s cornering limits, it automatically ensures smooth handling via minor corrective actions.

Credits: wilswong