In the A6, Audi has a car able to meet and beat the best of its rivals. With the addition of the special addition Le Mans model, the proposition looks stronger than ever. Beforehand, the S line was the premium spec A6, but now the Audi buyer has a real selection headache.

Even some time after the event and following the third successive victory, a diesel car winning the Le Mans 24-hour endurance race still sounds faintly bizarre. I almost feel compelled to check the official website to confirm that I hadn't had some sort of demented waking dream but Audi TDI power really did take the spoils at the La Sarthe circuit in 2006, 2007 and 2008. To commemorate these victories Audi is offering the Le Mans special edition. The car is based on the S line trim and includes stylish extra features.

Gone are the days when base specification A6 models were fitted with puny engines. This did Audi's image no good and the Le Mans model has two powerful engines - a 178bhp 2.7-litre TDI turbodiesel and a 233bhp 3.0-litre TDI with Quattro all-wheel drive. You can only upgrade to this stylish spec when you buy the 2.7TDI or the 3.0TDI Quattro S line A6 models. There is a choice between a manual six-speed gearbox and automatic transmission in both engine sizes and the ESP system can be momentarily disabled by tapping the dash mounted button, useful when accelerating on gravel or deep snow.

Diesel doubters will probably never really come to terms with Audis domination at Le Mans. Buy this Le Mans model and you'll have even more ammunition to flummox them with. The 2.7TDI goes from 0 to 62mph in 8.3s, with a maximum speed of 139mph and the 3.0TDI goes from 0 to 62mph in 7.1s and has a top speed of 150mph.

The key styling feature is that prominent grille or, as Audi prefers to call it, the 'single frame'. Look beyond that and you'll notice the curvaceous flanks, topped and tailed by a sharp longitudinal crease line that forms a definite hip and the rising edge in the door sills that creates a great deal of tension and shadow in the A6's profile. In this special edition version, Le Mans badges can be found on the side wings beneath the indicator lenses.

"You can only upgrade to this stylish spec when you buy the 2.7TDI or the 3.0TDI Quattro S line A6 models.."

Compared to the old generation A6, the overall length of this one has swelled to 4,916mm, up a whole 121mm over the previous car. The boot is a whopping 546 litres in all saloon models (or there's an Avant estate option), which is not only bigger than the 5 Series and the E-Class but also manages to put this car's big brother, the A8, in the shade.

Prices range between £25,519 and £36,610. Both models are available as a saloon or for a premium cost you can upgrade to the Avant touring model. Peer inside and there's Milano leather upholstery, heated front sports seats, rear acoustic parking sensors and upgraded LED interior lighting. On top of that, there's standard metallic or pearl effect paintwork. The S-line trim level is already generously specified with 30mm lowered sports suspension, an uprated braking system, cruise control, fascia inlays in brushed aluminium, a three-spoke sports steering wheel and Audi's Multi Media Interface controlling a 10-speaker audio system with CD changer.

The bottom line seems to be that if you want a very big car, you'll need to pay for it in terms of ongoing costs, if not in upfront purchase price. The 2.7TDI engine has CO2 emission figures of 225g/km and a combined fuel cycle of 33.2 mpg while the 3.0TDI engine gives emits 215g/km of CO2 and has a combined cycle of 34.9mpg. The 2.7TDI has an insurance group rating of 15 where the larger engine is 16.

One area where the A6 seems to mar its otherwise excellent record of achievement is potentially rather surprising. When it comes to residual values, the big Audi doesn't square up to some of its class-competitors. It does boast a cheaper list price which will swing the decision for many though.

The Audi Le Mans edition aims to take the luxurious A6 range to new heights of style. As with the whole A6 line-up, the Le Mans is a car that rewards you for doing your homework. As one of the least expensive ways of buying a German executive car with a premium badge, it has a head start right from the word go. Getting the most metal for your money might not be the ethos of this premium sector but it's one that will appeal to those looking for plenty of family space or those merely wanting to make the most stylish splash in the executive car park. Certain Audi trademarks can be taken for granted - the build quality is excellent, there are some great engines available, the attention to ergonomics is quite brilliant and with the Le Mans, you are getting arguably the most stylish vehicle in the A6 range.

Other areas aren't quite so well resolved. In making the A6 handle better, Audi has allowed ride quality to deteriorate. The A6 is also a car that suffers in most objective technical comparisons with its BMW rival from Munich. It nevertheless fills a niche and one which judging by current sales figures is expanding quite nicely.