The coasting function works between 34 and 100 mph (55 and 160 kph) to save precious fuel.
Ahead of its highly anticipated reveal set for next month, the all-new Audi A8 is back in the news yet again as the peeps from Ingolstadt have decided to spill the beans about the flagship sedan’s green credentials. Standard across the entire range will be a mild hybrid system consisting of a water-cooled 48-volt alternator starter mounted on the front side of the engine and complementing the regular pinion starter. Audi points out the latter will only kick in during cold starts. Also part of the mild hybrid setup will be a lithium-ion battery pack mounted in the trunk with a 10-Ah charge carrier capacity and a 48-volt system.
The full-size luxury sedan will be equipped with a highly advanced coasting function available from 34.2 to 99.4 mph (55 to 160 kph) once the driver takes his foot off the accelerator. In this speed range, the A8’s engine will be completely shut off whenever possible to save fuel and it will remain that way for up to 40 seconds. After the driver presses the gas pedal, the combustion engine is activated immediately without any delays in acceleration. This will be possible thanks to the aforementioned 48-volt belt alternator starter (BAS) permanently connected to the engine and ready to fire it up right away at all times.
Audi’s engineers have also come up with a clever start/stop system active from 12.7 mph (22 kph) and incorporating a new function dubbed “predictive convenient starting.” Once the A8’s front-mounted camera and sensors detect the car in front starts moving, the engine is automatically turned on even if the driver still has his foot on the brake pedal, so that he’ll be able to drive off quicker and consequently improve the flow of the traffic. The onboard tech will also be smart enough to detect if the posh sedan is dangerously getting too close to the car behind it while in coasting mode.
Thanks to the mild hybrid system and the clever powertrain management, Audi says fuel consumption is reduced by up to 0.7 liters (0.2 gallons) / 62 miles (100 km).
The fourth-generation A8 will be unveiled on July 11 at the Audi Summit event in Barcelona.