Stunning technology in new Audi
S8 loses two cylinders but gains more power, better fuel consumption
ELCIEGO, SPAIN— During a tour of a wine cellar at of one of Spain’s oldest wineries, I still couldn’t get my head around something I’d learned earlier in the day: The new Audi S8 uses speakers as engine mounts. Wait, what?
The 2012 S8 is the hot-rod version of the latest generation A8, which itself got revised in 2010, growing a bit dimensionally in the process. It gets the prerequisite S-rated increase in horsepower, firmer suspension, a discrete S body trim and the standard 20-inch wheels (21inchers are optional). It also gets the higher price; although pricing has not yet been determined, all indications are it’ll be near the $127,000 price tag of the 2010 S8.
Based on Audi’s flagship luxury liner, the S8 has a delightfully lush interior, the leather finish is beyond reproach and the seats feature 22way adjustability and heat — but no air conditioning to relieve your sweaty backside.
The S8 replaces the A8’s wooden trim with carbon fibre and brushed aluminum, and there’s soft, ambient interior lighting that emits a cool, bluish glow at night. My tester was equipped with a high-speed Wi-fi connection, though it won’t be available in North America due to the exorbitant price and low bandwidth we enjoy here.
Audi is among several automakers to reduce fuel consumption by replacing big, naturally aspirated engines with smaller displacement and turbocharging. Now rated at 10.2L/100 km using the European test cycle, the new 4.0-litre turbocharged V8 uses 23 per cent less fuel than the 5.2-litre V10 it replaces. To achieve these numbers, Audi resorted to what it calls “cylinders on demand” — the premise being that a number of cylinders are shut off (four in the S8’s case) under light cruising loads, thus further reducing fuel consumption (Audi claims 10 per cent at 100 km/h). It’s the system that requires the use of the under-engine woofers. When the engine control unit switches off the designated cylinders, it essentially converts the engine into a V4, thus introducing torsional vibration into the chassis, which at certain speeds feels like an unbalanced wheel. To counter this, the engine mounts incorporate a computer-controlled speaker-like device — a coil of wire wrapped around a permanent magnet — to match this vibration in amplitude and frequency, but with phases opposed 180 degrees.
This cancels most of the vibration, the remaining “noise” being taken care of by the sound system, which uses microphones to monitor and pick up cabin noise.
It then emits a sound-cancelling frequency through the rear subwoofer. It’s the same principle used in sound-cancelling headphones and it was developed for the S8 in conjunction with manufacturer Bose.
Despite its sportier penchant, the S8 handled itself with stately sophistication on the road. Its suspension, although firmer than on the A8, did a great job of isolating the cabin from pavement irregularities while providing a sporty and level ride through turns.
While cruising the highway, the transition from eight to four cylinders and back was imperceptible, only an icon in the instrument panel lets you know that half of the engine is working. Acceleration instantly called up the dormant cylinders.
You’ll be looking for passing opportunities with this car because the S8 delivers its power to the ground smoothly and swiftly. Unfortunately the exhaust note is subdued, so you don’t get the aural pleasure the V8 is capable of delivering.
The quiet exhaust contributed to a quiet interior, which allowed maximum enjoyment of the crystalclear, optional 1,400-watt Bang & Olufsen sound system, though I’m sure cranking up the volume would have drowned out the engine even if the exhaust system were ripped out. Bose provides the standard sound system and it pumps out a paltry 600 watts.
Downsizing the engine doesn’t mean downsized power, and the V8 produces 520 horsepower, 15 per cent more than the former S8’s supplanted V10. It also produces 479 lb.-ft. of torque from 1,700 r.p.m., up from the previous engine’s 398 lb.ft., which peaked at 3,500 r.p.m. The all-aluminum engine uses an inverted cylinder head layout, similar to the one used in the latest generation BMW M5, with the intake tracts located outside the V and the exhaust tracts inboard, with the twin turbochargers placed atop the engine. Of course, no preview drive of a lavishly equipped, premium luxury sedan would be complete without some time on a racetrack. So Audi arranged a few laps around the Circuito de Navarra racetrack, about 60 kilometres east of Elciego in Northern Spain. Several driving modes can be called up using the console-mounted control panel. These modes adjust the active air suspension for ride height (25-mm range) and firmness, and alter steering effort, engine power characteristics and auto shifting in the eight-speed automatic. The car was set up with the most aggressive settings for the track, and it was also equipped with the optional carbon fibre/ceramic brake discs.
The first thing that was noticeable at speed was the high rigidity of the aluminum spaceframe chassis.
The next was the level of control Audi’s latest quattro all-wheel-drive system provides. It combines electronic stability control, standardequipment torque vectoring (which uses the brakes) and a sport differential (which transfers more torque to the outside wheels in a turn) to aid steering. When encountering a mid-turn oversteer, I stepped on the gas and the system instantly corrected and turned the car in.
The S8’s substantial output pushed the 1,975 kg (4,354 lbs.) sedan forcefully out of corners and those trick brakes slowed it safely from about 180 km/h, though they did exhibit some fade after about a lap. Zero to 100 km/h time is 4.2 seconds, 0.7 sec. quicker than the 2010 S8. Using the steering wheel paddles to shift the transmission manually provided quick, positive gear changes with little lag between ratios.
Available driver assist systems include adaptive cruise control, blind spot assist, driver fatigue warning, parking assist cameras and night vision assist, which uses an infrared camera to identify pedestrians at night.
The 2012 S8 is scheduled to arrive in Canada in September. Only about 40 will be available. Travel for freelance reviewer Costa Mouzouris was provided by the automaker. mouzourisc@gmail.com