Used Vehicle Review: Audi A8, 2004-2010

By Chris Chase

The second generation of Audi’s flagship A8 sedan arrived in Canada in 2004, following its European introduction in late 2002. The lineup began as a single V8-powered model, the long-wheelbase A8L; a regular-wheelbase model and a second long-wheelbase variant powered by Audi’s W12 engine joined the range in 2005.

The A8 is notable for its aluminum construction and fully-pneumatic suspension, which can be raised and lowered by the driver, or set to lower automatically at highway speeds, for greater stability.

The base engine was a 4.2-litre V8 (335 hp/317 lb-ft of torque), while the W12 – essentially two Volkswagen VR6 engines “siamesed” at the crankshaft – displaced 6.0-litres and produced 450 horsepower and 428 lb-ft.

In 2006, the A8 got Audi’s single-frame grille, a controversial look that nonetheless gave the car more visual weight.

For 2007, Audi added the S8, a high-performance variant powered by a 5.2-litre V10 shared by the smaller S6.

2008 Audi A8; photo courtesy Audi. Click image to enlarge

The styling was refreshed again in 2008, with a revised grilled (again) and LED taillights. In 2010, the S8 and long-wheelbase model W12 models were discontinued as Audi prepared for the arrival of the forthcoming 2011 model.

With the base V8 engine, the A8’s fuel consumption estimates of 13.1/8.8 L/100 km (city/highway) are more reasonable than you’d expect for a car this large. W12 and S8 models’ figures of 16.4/10.4 L/100 km and 15.9/10.3 L/100 km seem more in line with the kind of fuel consumption typically associated with luxury flagship sedans. A 2006 model I tested averaged 9.5 L/100 km on a highway trip from Ottawa to Hamilton, Ontario.

Typically, big German cars are expensive to maintain, and it appears the A8 is no exception. On 2004 models, at least, getting the oil changed is a pricey procedure thanks to the location of the oil filter. If you want to save a few bucks, take part of a Saturday and do it yourself; nothing about it is terribly difficult, but requires the removal of a couple of other components to get at the filter. This thread provides a good walk-through. (http://www.audiforums.com/forum/showthread.php?t=150293)

2009 Audi S8; photos by Paul Williams. Click image to enlarge

Most of the A8’s common issues are listed in this thread at AudiForums.com. Here’s a rundown of what you’ll find at that link. Note that while this thread says these problems are mostly limited to 2004 models, Consumer Reports lists the same troubles in 2005 and 2006 models (those are the only two years for which CR has data on the A8).

Overheating is common and typically caused by a bad thermostat. Radiator leaks are quite common, too; here’s another thread on that.

The front suspension’s upper control arm bushings are prone to wear, causing a clunking sound during turns. The cause, apparently, is that the A8’s larger control arms use the same bushings as the smaller A4, and the extra stress causes accelerated wear. CR also mentions the A8’s air suspension as something to watch for. These systems aren’t typically trouble-free in the long run and cost big bucks to repair.