Audi S8

Audi S8

In the last quarter of 2005, Audi introduced the latest Typ 4E S8 5.2 FSI quattro, based on its Volkswagen Group D3 platform stablemate, the Audi A8.

Audi's factory performance claims for the V10 S8 indicate a 0-100 km/h (62 mph) time of 5.1 seconds (whilst consuming "SuperPlus" / "EuroSuper" 98RON unleaded petrol). This places the S8 in a competitive range with the Mercedes-Benz S63 AMG and S600 (powered by a twin-turbo V12), the BMW 760Li (powered by a naturally-aspirated 12-cylinder engine), and the company's own A8L W12. Top speed is electronically limited to 250 km/h (160 mph).

Powertrain

This latest D3 S8 is powered by an all aluminium alloy 5,204 cc (317.6 cu in) Fuel Stratified Injection (FSI) 40-valve 90° V10 petrol engine, derived from the Lamborghini Gallardo 5.0 litre V10. A longer stroke and wider bore increases the displacement of the engine, and produces more torque at lower revs, making it more suitable for the larger and heavier Audi. It has been retuned to produce 331 kW (450 PS/444 bhp) at 7000 rpm and 540 N·m (400 ft·lbf) of torque at 3500 rpm. It utilises twin chain-driven double overhead camshafts (DOHC), and variable valve timing for both intake and exhaust valves. Engine management is by way of Bosch Motronic MED 9.1 engine control unit, which controls the mapped direct ignition, ten individual spark coils, common rail cylinder-direct sequential mulit-point fuel injection, and drive by wire throttle.

A sports-optimised six-speed tiptronic automatic transmission (gear ratios - 1st: 4.171, 2nd: 2.340, 3rd: 1.521, 4th: 1.143, 5th: 0.867, 6th: 0.691) with "Dynamic Shift Programme" (DSP) and "sport" mode, with steering wheel mounted paddle-shifters, is the only offering. Output is transmitted via the trademark quattro permanent four-wheel drive system, initially using the Torsen T-2 50:50 dynamic centre differential, and from 2008 model year, utilising the latest Torsen T-3 asymmetric dynamic centre differential, with a 'default' torque distribution of 40% to the front axle and 60% to the rear. Final drive ratio is 4.055, and is assisted with Audi's "Electronic Differential Lock" (EDL).

Suspension, steering, brakes, tyres

The S8, like its related A8 utilises a multi-link suspension layout front and rear, with pressurised air springs. However, for the S8, the effective spring and damper rates are noticeably firmer, along with re-engineered suspension mounts. "Servotronic" speed-dependent power assisted rack and pinion steering point the S8 in the desired trajectory.

The brake system consists of radially ventilated discs all round, the fronts sized at 386 mm (15.2 in) in diameter by 36 mm (1.42 in) thick, and the rears at 335 mm (13.2 in) by 22 mm (0.87 in). The discs are clamped with black painted dual-piston calipers up front, and a single-piston sliding caliper at the rear, coupled to an electro-mechanical parking brake. A Bosch ESP 8.0 Electronic Stability Programme, with Anti-lock Braking System (ABS), brake assist, and Electronic Brakeforce Distribution (EBD) complete the brake system.

Standard alloy wheels consist of 9Jx20" cast aluminium alloy "S design", shod with 265/35ZR20 99Y performance tyres. A direct-acting tyre pressure monitoring system is also standard.

Body and interior

The S8 includes subtle detailing to distinguish it from its related A8. The trapezoidal "single-frame" grille bears the characteristic Audi "S" model vertical strut detail which are highlighted in a chrome finish. "S8" badging is displayed front and rear, whilst "V10" badges are displayed on each front wing below the side-repeater indicators. The rear boot-lid incorporates a subtle rear spoiler, and the rear is finished with four oval exhaust tailpipes.

Adaptive xenon-plus high-intensity discharge (HID) headlamps include static turning lights, along with 'swiveling' dynamic cornering lights. Daytime running lamps are five LEDs incorporated into a cloverleaf designed reflector, incorporated into the main headlamp housing.

The interior equipment includes two-colour leather-clad sports seats, a widescreen colour display for the Multi Media Interface (MMI), and white illuminated needles for the instrument dials.

An optional 1000 watt digital Bang & Olufsen Advanced Sound System can be specified to replace the standard BOSE surround sound system. Other notable options include the "Advanced Parking" system, which includes a rearview camera, whose output is displayed on the colour MMI monitor, with "trajectory" lines which move in conjunction with steering wheel movements.