The bulk of the updates are found under the A6's hood.

Audi has published a full set of details about the updated Euro-spec A6 ahead of its public debut at the Paris Motor Show next month.The bulk of the changes are found by looking under the hood, where the A6 gains revised engines that meet the strict Euro 6 emissions norms. The diesel-burning lineup includes five TDI engines that range from a 150-horsepower 2.0-liter to a twin-turbocharged 3.0-liter rated at 326 ponies. Buyers who prefer unleaded can choose from three TFSI units that produce between 190 and 333 horsepower.

The 326-horsepower TDI is bolted to an eight-speed automatic transmission. All other engines are linked to either a new six-speed manual gearbox or a seven-speed dual-clutch unit controlled by shift paddles. Both front-wheel drive and all-wheel drive models are available.

Interestingly, the highly-efficient A6 2.0 TDI ultra is equipped with springs crafted out of fiberglass-reinforced polymer, a setup that helps shave nearly 10 pounds from the car's overall weight. The A6 TDI ultra returns 56 mpg in a mixed European cycle, making it the cleanest member of the A6 lineup.

At the other end of the spectrum, the performance-focused S6 gets a 450-horsepower version of the current model's 4.0-liter TFSI V8 engine. The 30 extra horses help the sedan reach 62 mph in just 4.4 seconds, while Audi's Cylinder-on-Demand technology keeps gas mileage in check. The range-topping RS6 Avant carries on with no major mechanical modifications.

The visual updates are decidedly minor and largely limited to an updated radiator grille, sharper headlights, a new bumper and redrawn tail lamps out back. New wheel designs and paint colors round out the updates.

The facelifted Audi A6 is scheduled to go on sale across Germany before the end of the year with a base price of €38,400, a sum that converts to approximately $50,500. Audi has not revealed if the U.S.-spec A6 will undergo similar updates.