Audi A8

It's been six long years since a major Audi A8 update and the quad-ring brand looks as though it's finally ready to deliver its new heavyweight. The new Audi A8 has been caught testing on multiple occasions and we've come across it again testing at where else but the Nurburgring ahead of the A8's 2010 Detroit auto show debut.

As in the past, the car our spy photographers spotted is heavily camouflaged so as not to give away any too many hints about its new body work. Still, we've gleaned enough from our growing collection of pictures to see that Audi has updated the A8's styling with a sharper, edgier look that should make it stand out in Audi's field of rounder designs. Accenting the ultramodern look are the latest version of Audi's swoopy LED driving lights and possibly a slight increase in size to give it a more commanding presence.

The big story, though, is under that swirly hood. Our latest intel suggests that Audi is going to expand the A8's engine line-up even further and offer a 200-hp twin-turbodiesel four-cylinder to compete with models like Mercedes-Benz' BlueEfficiency four-cylinder S-Class. On the other end of the spectrum, the mighty W-12 engine is expected to not only live on but increase in power and displacement to over 500 hp and 6.5L. It will also reportedly pick up direct injection to improve power and efficiency.

In between, a new, 400-plus-horsepower supercharged V-8 is expected to arrive in mid-2010 with cylinder deactivation technology while the V-10 engine is expected to be put out to pasture. Also rumored is a new version of Audi's supercharged V-6 that's been outfitted with twin turbos instead, offering even more than the current 333 hp.

Both gasoline and diesel engines are expected to be offered in Europe with either FWD drivetrains for the smaller engines or AWD layouts for the larger ones. Plans for the U.S. aren't known yet, but expect fewer engine options on these shores as the current A8 only offers one engine, a 4.2L V-8. The twin-turbodiesel four will almost certainly stay in Europe, but with Audi's recent push for diesels in America, it's possible the new A8 could offer a larger diesel engine when it goes on sale here in late 2010.