Audi's new 'volts wagon' … and Mercedes' AA Class

This month sees the debut of Audi's all-new A8 range, the first in the Brand's history to feature electrified drivetrains as standard. Featuring a 48-volt primary electrical system, these new A8s promise a new level of refinement, performance, and – of course – economy.

The new volts wagen from Audi – The all-new Audi A8 range will be the first in the brand’s history to feature an electrified drivetrain as standard. Its combustion engines will be equipped with mild hybrid technology based around a 48-volt electrical system which features as the primary electrical system for the first time. 

The A8's hybrid drive comprises two main components: a watercooled, 48-volt belt alternator starter (BAS), and a lithium-ion battery that acts as an accumulator. The BAS complements a conventional pinion starter, which is used only for cold starts, while the lithium-ion battery (stowed in the luggage compartment) has a 10Ah charge carrier capacity.

BAS's advantage becomes clear when approaching roundabouts or red traffic signals. If the traffic signal turns green during braking, while the vehicle is coasting to a stop or if a gap appears for the driver to move into, and the driver releases the brake, the combustion engine is started immediately. There's no delay in acceleration, thanks to the belt alternator starter, which is permanently connected to the combustion engine.

The fourth-generation A8s feature a new noiseless coasting mode, available between 34mph and 99mph, which switches off the engine altogether, for up to 40 seconds, giving zero-emissions. The moment the driver steps on the throttle, the BAS swiftly and smoothly restarts the engine. 

The new A8's stop/start function has been improved, too. It's now active from 14mph, and it can even distinguish between different traffic situations. If the road is clear, the BAS starts the engine promptly, so you can drive off swiftly. After a long standstill, or if the drive wants to turn up the aircon, the engine start up switches to extra smooth and silent mode. It even has predictive starting: if the vehicle in front of you moves off, the engine starts even if the brake is applied.

Of course, one of the big factors in hybrid tech, is the recuperation or regeneration of energy, and the A8 comes with some sophisticated management just for this. On-board computers process route data, front-facing camera views, and various sensor data, and calculates the best time to coast or recuperate (the system can even recuperate energy if you get too close to the vehicle in front). The upshot, is that fuel consumption is reduced by as much as 0.7 litres per 100 kilometres.

The new Audi A8 debuts on 11th July, at the first Audi Summit, in Barcelona, Spain. 

Further information on powertrain development at Audi is available at

www.audi-mediacenter.com/en/techday-combustion-engine-technology.

Of course, Audi isn't the only German manufacturer to look into electrical power … Mercedes-Benz are also on the case, as this video highlights … possibly …