The A8 L also gets increased performance, with the 6.3-litre W12 engine in the A8 L quattro going up to 493bhp. Audi says this engine has the best economy in its class, with 24.1mpg combined and 270g/km of CO2 emissions.
For even more performance, the S8 comes equipped with a 4.0-litre TFSI engine producing 513bhp. That means the S8 can cover 0-62mph in 4.1 seconds while also acheiving up to 29.4mpg and 225g/km CO2 emissions.
Audi has also released details of its A8 hybrid, which combines a 2.0-litre TFSI petrol engine and an electric motor to acheive a combined output of 242bhp and 354lb ft of torque. The hybrid can travel at up to 62mph on pure electric power, and has an electric-only range of 1.9 miles. The engine returns up to 44.8mpg with CO2 emissions of 144g/km, and is available in both standard and long wheelbase A8s.
Audi says it has resculpted the bonnet of the A8 to enhance its grille, the bumper and the headlight clusters - which gives the A8 a sharper front-end view. The same is true of the rear, where new LED tail light designs have been integrated alongside a new twin exhaust system.
A new lighting system that uses 25 LEDs each is also present, which Audi says enables the A8 to react to changing situations faster than ever before, such as automatically dimming headlights when another vehicle is detected. The lighting system also uses data from the on-board satellite navigation to predict conditions on the road ahead and maximise light distribution.
Elsewhere, Audi's Drive Select system is now standard on the A8, while options for the interior include new colour schemes and new trim materials. Among the more lavish interior options is a new stereo system designed by Bang & Olufsen, front seats with ventilation and massage settings, and power-assisted closing doors. Optional safety equipment includes Audi's Active Lane Assist, a park-assist system with 360-degree display, and a Heads Up Display for drivers.
The Audi A8 is being offered in three specification levels in the UK, dubbed SE, SE Executive and Sport Executive. Standard SE models get 18-inch alloy wheels, plus enhanced electromechanical steering and all-LED headlights. SE Executive models get additional equipment, while top-spec Sport Executive models get new MaxtrixBeam LED lighting as well as internet connectivity.
Prices for the Audi A8 start at £58,800 for a 3.0-litre TDI quattro in SE trim, rising to £61,405 for the same engine in Sport Executive trim. Hybrid models range from £62,900 to £66,865 for a LWB version, while the LWB A8 with a 4.2-litre TDI quattro engine ranges from £75,970 to £79,570 depending on trim. The most expensive model in the range so far, the S8, is priced at £79,900.
Audi has yet to reveal prices for the LWB W12 model.
The A8 will go up against the new Mercedes S-class as well as the BMW 7-series in the UK. Read Autocar's first drive of the new A8 here.