The label ‘Black Edition’ used to typify the type of car which was more of an iron fist in velvet glove – subtle on the outside but hard as nails underneath. Now thanks mainly to Audi and Porsche, a black edition is merely a stealthy mainstream model – another means of sub-dividing an already segmented niche model.

For Audi’s A6 and A7, the niche within which the Black Edition versions derive from are the S line models – which means they come as standard with the lowered sports suspension. To this is added 20-inch diameter wheels in the A6 Saloon and Avant, or 21 inches in the A7 Sportback, with a dark titanium finish.

Each model features a black finish for the grille and number plate surrounds and the window frame strips, and dark privacy glass extending from the B-pillar rearwards. The A6 Avant Black Edition is also equipped with black roof rails.

Inside, their cabins feature distinctive Piano Black inlays, complementing the sports seats upholstered in black Valcona leather and the black interior headlining. A BOSE surround sound system, DAB digital radio and the Audi Music Interface (AMI) for iPod connection is added on A6 and A6 Avant models, while the A7 Sportback Black Edition gains the BOSE upgrade, but already features DAB radio and AMI as standard.

In the A6 range, the Black Edition specification is available in all models from the 177PS 2.0-litre TDI upwards – apart from the S6, including the formidable 3.0-litre BiTDI engined version with its 309bhp and 479lb-ft (650Nm) of torque. For the A7 Sportback, Black Edition can be selected in all versions bar the front-wheel-drive 3.0-litre TDI 204PS and the S7 Sportback.

The A6 Black Editions are priced from £35,010 to £49,185, or from £36,970 to £51,025 for the Avant. The A7 Sportback Black Edition is priced from £50,575 to £56,785.

All versions are available to order from this month, with first deliveries arriving in early 2013.