The upcoming Audi A8 will join the new Mercedes-Benz S-Class in having a 48-volt power system that turns these luxury flagships into more fuel-efficient super-mild hybrids.
The battery is charged by a belt-driven alternator that gathers energy during braking. The battery then assists the gas or diesel engine not only for fuel savings but for slight boosts in power and torque translating to about 16 horsepower and 44 ft-lbs of torque.
This drivetrain has a few tricks up its sleeve that we’ve seen on traditional hybrids. The A8 will be able to coast for up for 45 seconds with the engine off. When it’s time to accelerate, the target speed is reached with the help of the electric battery. No need to worry when the battery is low on regenerative brake juice, either; this car will have a separate 12-volt battery to power electrical components and help with cold starts.
According to Audi, this system can help reduce the fuel consumption of a V6 by up to 0.7 liters per 100 km—which translates to 0.18 gallons per 62.14 miles. That doesn’t sound like spectacular fuel savings, but every little bit helps. In another effort to reduce fuel consumption in the A8, Audi is working on cylinder-on-demand technology as well.
The car hasn’t been unveiled yet, but expect something similar to the Prologue concept pictured above.
If Audi does a good job engineering this thing—and we're sure it will—it should make for a respectably efficient luxo-barge that doesn’t compromise on performance. An official unveiling of the A8 is coming on July 11th in Barcelona, where Audi will also reveal the car's cutting-edge autonomous driving tech and new design language.
