2015 Audi A8 4.0-liter Twin-turbo V-8 Engine

Audi has made countless revisions to the current-gen Audi A8's engine lineup, so it's no surprise that the updated sedan will arrive with a more powerful V-8. The 4.0-liter twin-turbo V-8 entered the lineup in model year 2013, providing a healthy 420 hp and 444 lb-ft of torque. The updated version gets 9 more horses (new torque figures weren't available), so don't expect a drastic change in the 4.2-second 0-60 mph time we achieved in a 2013 Audi A8 L 4.0.

The base model's 333-hp, 3.0-liter supercharged V-6 will carry over, as will the diesel-powered Audi A8 L TDI and its 3.0-liter turbodiesel making 240 hp and 406 lb-ft of torque. Audi says all engines are slightly more efficient thanks to "friction-reducing measures" that shave consumption by up to 10 percent.

The interior design hasn't changed, but the Audi A8 still coddles passengers with a dizzying array of luxury packages and options, including an Executive Rear Seat Comfort Package that includes a cooler box and a passenger-side rear-seat footrest.

Among the new interior finishes offered for the 2015 Audi A8 are silver-hued wood accents and leather surfaces. Passengers riding in the Audi A8 L long-wheelbase model should enjoy more room, too, thanks to an increase in dimensions. Audi didn't provide new interior dimensions, but the current Audi A8 L provides an already generous 42.9 inches of rear legroom. 

The Audi A8 features Audi's first application of its Matrix LED lighting system, an optional item that constantly adjusts illumination intensity and direction. Each headlamp unit contains 25 LEDs and is controlled by an intelligent cornering light system.

In addition to the advanced lighting system, the 2015 Audi A8 gains a new active lane system that will make steering adjustments. The night-vision system has been updated to recognize large animals in addition to pedestrians. And parking assistance joins the lineup.