Audi has been battling for years to steal new-car buyers away from its German rivals Mercedes-Benz and BMW, and at last the manufacturer seems to be making gains, at least with the A4 and TT models. But when it comes to its flagship, the A8, Audi struggles to capture hearts and wallets in the same way, and that’s good news if you fancy picking up a used example.

Introduced in August 2003, the second generation Audi A8 continued with the now familiar formula of all-aluminium space frame, V8 engines and quattro four-wheel drive. But now the A8 had a new weapon — diesel power.

It came in the shape of an impressive 4 litre V8, producing 274bhp and 479 lb ft of torque at 1800rpm. The result? A luxury saloon car that will sprint from 0-60mph in 6.4sec, reach 153mph and still return 30mpg in mixed motoring.

But buying a new A8 4.0 TDI was not a cheap option. It cost £6,000 more than the equivalent 3.7 litre V8 petrol and £2,000 more than the 4.2 litre. A new 3 litre entry-level diesel was introduced in January 2004 for some £10,000 less than its big brother, and although its 233bhp engine is no match for the 4 litre, driven in isolation it is still a very impressive performer. Fuel consumption improves by around 10% and the quattro drive ensures handling is just as sweet.

The only problem for secondhand buyers will be finding either diesel model for sale at a reasonable price or sensible mileage, because owners tend to hang on to them. It will be late in 2007 before secondhand examples become more readily available.

If you want a good-value luxury saloon now rather than later, you’ll have to opt for the slightly less sought-after but equally good petrol models. The best bargains are to be had on the entry-level V6 model, also added in 2004. Lacking the quattro drive and using a multitronic six-speed CVT automatic gearbox, it brought the new-car list price down to a more attainable £45,000. Today a three-year-old example can be yours for a touch over £20,000.

In terms of specification there is little missing from the Audi A8’s standard equipment list with leather, zoned climate control, alloys, multi-disc CD player and a smattering of airbags all standard. Larger-engine models gain electric memory front seats and larger alloys, although the list of options, such as radar-controlled cruise control, satellite navigation and upgraded stereos, also tempted many buyers when new. While many of these are nice to have, only the sat nav adds much to the car’s resale value, and then no more than around £750 on a one or two-year-old car.

On the road, the A8 performs somewhere between a sporting saloon and a luxury coach. The coach part refers to the car’s interior space — it’s huge. Even without the extra 13cm of rear legroom offered by the LWB (long-wheelbase) model the rear space is vast. Head and shoulder room are generous, in both front and back, and even with five adults on board the A8 never feels cramped.

In terms of driving dynamics, the A8 feels distinctly uncoach-like, even sporty. This is due in part to the car’s incredibly rigid aluminium space frame, but also to the suspension setup. Some luxury car buyers will be disappointed that the A8 doesn’t soak up bumps as well as certain rivals, but others will appreciate the enhanced handling.

Audi prides itself on superb build quality and this generation of A8 pushes those standards even higher. On secondhand examples expect factory-fresh interiors, and even cars approaching 100,000 miles shouldn’t show much wear on the upholstery. The car’s variable service intervals sometimes make checking for missed services tricky, so inspect dates and mileages carefully.

The Audi A8 may not be the most desirable luxury car in the world, but this second generation car takes Audi a big step closer to that goal. If you’ve always fancied owning an Audi flagship then a good used example is the most economical way to go about it.

Boot 500-litre boot is among the best in class and has neat automatic opening/closing operated by key fob

Dashboard Centre console is dominated by MMI (Multi Media Interface), which works in a similar way to the BMW 7-series system but is more instinctive

Stereo Standard nine-speaker stereo with six-disc CD player in glove box is good; factory upgrade is spectacular

Spare wheel Full-size spare wheel on models with rims of 18in or less

Satellite navigation A desirable option on used examples adding about £750 to used prices

Keyless entry Wonderfully simple — just press the starter button to fire the engine and off you go

Diesel 4 litre V8 diesel sounds good, 3 litre diesel is slightly quieter and offers 33mpg-plus economy

Gearbox Auto transmission standard on all models but nonV8 petrol versions get multitronic system instead of tiptronic

LWB (long wheelbase) Additional 13cm of rear legroom unfortunately adds a hefty £2,500 to secondhand values

VITAL STATISTICS

Model Audi A8 4.0
Engine TDI quattro 3936cc, V8 turbodiesel
Power 274bhp
Transmission Six-speed tiptronic automatic
Fuel 29.4mpg (combined cycle)
Acceleration 0-60mph: 6.4sec
Top speed 153mph

THE ONE TO BUY

Audi A8 4.0 TDI 2003 03 with 40,000 miles on the clock. Pay £29,500 at a dealer or £28,000 privately

OR FOR SIMILAR MONEY

2004 04 BMW 730d Sport
2004 04 Mercedes-Benz S 320 CDI
2004 54 Lexus LS 430
2005 54 Jaguar XJ8 3.5 V8
2005 55 VW Phaeton 3.0 V6 TDI 4Motion