Exploring The Audi A8’s Cool Future Tech
Our name promises to keep you abreast of what’s now, what’s new, and what’s next in the car biz. Our Trend and Technologue pages provide a crystal-ball/tarot-card prediction of just how wonderful motoring could be in the future. Then it usually falls to luxury flagship sedans such as the 2018 Audi A8 L to prove or disprove our fearless predictions. This one weighs in on our predictions of SAE Level 3 autonomy, active electric suspensions, 48-volt electrical architecture, and mixed-material body structures and delivers several we haven’t weighed in on such as laser scanners, laser body welding, and last but certainly not least—foot massagers! Let’s take a closer look at the bleeding-edge tech Audi will be rolling out next summer.
Electric Active Suspension
My very first Technologue column back in December 2004 covered an electromagnetic active suspension Bose was working on. This is as close as any automaker has come to fulfilling that prediction, but the electromagnetic rams are replaced by an electric motor about the size of a small alternator at each corner. These connect to the suspension links kind of like an active anti-roll bar would, and they’re capable of pushing each wheel up over a bump or down into a pothole to smooth out the ride. These electric motors control major body motions such as roll, pitch, and dive, which simplifies the jobs left to the air springs and dampers. The former merely have to level and support the car’s weight (at one of four ride heights) while the latter focus on damping individual wheel motions. Engaging the Dynamic mode of Drive Select tenses the dampers slightly and reduces the amount of roll the active suspension allows. The optional Audi AI suspension adds about 110 pounds to the A8.
Each motor routes its torque through a 200:1 belt-drive and strain-wave gear train to a titanium torque tube, which in turn twists a torsion bar and lever arm that connects to the suspension link. On a rough road requiring continuous up-and-down motions, these motors can peak at 2 kW each (7kW max for the system). Each corner is capable of applying 811 lb-ft of torque to the corner (them’s Bugatti W16 torques!). Like the Bose system, these motors regenerate energy on the way back down off a bump or up out of a pothole. That energy doesn’t power the car at all, but it reduces the average power draw of the system to between 10-200 watts. Light bulb power promises a magic carpet ride!
Many German companies toyed with tripling electrical-system voltage in the ’90s, but by November 2012 I reported on concerted industry efforts to quadruple it. The VW Group has led the charge with last year’s Bentayga/Q7 platform introducing 48-volt active anti-roll bars fed by a 12-volt primary architecture. The A8 stakes its claim as the first production car with a primary 48-volt system that down-converts to 12 volts for running bulbs, switches, and infotainment gear. (Read the owners’ manual carefully before offering or accepting a jump start from a new A8!)
This 48-volt energy powers the optional active suspension as well as some level of hybridization on all A8s. The initial 3.0-liter turbo V-6 and later 4.0-liter V-8 engines will both feature a compact belt-driven alternator/starter capable of shuttling energy back and forth between the powertrain and a small 48-volt lithium-ion battery at a rate of about 12 kW. The stronger battery and motor enables much more frequent auto start/stop operation, for up to 40 seconds of silent “sailing” at speeds of 34-99 mph and when coasting down to a stop from 14 mph. An e-tron plug-in hybrid model might eventually arrive stateside with a much bigger 14.1-kWh battery under the trunk floor that enables up to 31 miles of electric operation inside zero-emissions zones. A bigger motor sandwiched between the engine and transmission helps the V-6 turbo deliver a total system output of about 449 hp and 516 lb-ft of torque. The e-tron model offers wireless inductive charging with a floor plate that rises up toward the car to deliver energy at a rate of 3.6 kW and 90 percent efficiency.
In addition to the aforementioned range-finding laser, the A8 has achieved full type approval to sell its laser high beam lights, but of course because our government fears technology (or perhaps wishes to keep us in the dark), U.S.-bound lasers are restricted to a range that extends just slightly past the LED high beam pattern (in Europe, the Laser doubles the high beam range). The 405-nanometer blue laser beam reflects off a material that turns the light white, and the laser unit itself is vastly smaller than the one that first appeared on Audi’s R8.