There isn’t an engine in the A6 range that feels out of its depth. Even the entry-level 2.0 TDI diesel has more than enough low-rev shove to haul along a fully loaded A6, plus you can overtake at high speeds with confidence. In fact, it never feels remotely underpowered, and is our favourite engine.
As you step up the engine range, you’re struck by how effortless the performance becomes. The 3.0 TDI is available in two power outputs; the 215bhp version pulls strongly from low revs, while the 268bhp one barely needs to be revved to keep up with traffic. The twin-turbo 3.0 BiTDI is astonishingly quick. If you must have six cylinders in your diesel A6, the 215bhp version has all the power you’ll ever need.
The only petrol is the V8-powered S6. This has a twin-turbocharged 4.0-litre engine with monumental mid-range punch.
All A6s bar the 2.0 TDI come with an automatic gearbox as standard. The 2.0 gets a six-speed manual ’box with a set of well-spaced ratios, although the optional seven-speed auto suits the car better. The auto can dither a little from a standstill, but otherwise it shifts gear quickly.
Audi A6 Saloon ride comfort
Well controlled over most surfaces
Like many cars at this price, the A6 is available with a variety of suspension set-ups. SE-spec cars get the most comfortable suspension, while S line and Black Edition versions come with lowered, stiffened suspension and larger wheels. The S6 gets air suspension, which is available as an expensive optional extra on the other models in the range.
SE models on their standard 17in wheels do a good job of smoothing out broken surfaces at low speeds and dealing with expansion joints on the motorway.
S line versions aren’t as comfortable, especially over sharp-edged bumps around town, but the ride is far from unbearable and is fine on faster roads. The 20in wheels of Black Edition models do the ride no favours, but the good news is that you can have your S line or Black Edition A6 with the SE-spec suspension for no extra cost, and we’d suggest you do.
The air suspension is impressive, but it doesn’t make the ride markedly more comfortable than the SE’s set-up, so we wouldn’t recommend paying the considerable extra it costs.
A BMW 5 Series, albeit one with the optional adaptive shock absorbers fitted, is the best-riding large executive car around. The A6 isn’t far off, but the BMW is better at rounding off bumps at all speeds.
Audi A6 Saloon handling
Not as sharp as some, but still pretty good for such a large car
The fact that the Audi A6 is lighter than most of its direct rivals helps it feel pretty agile for such a big car. Every version also grips well and feels composed when cornering, especially the S line and Black Edition models with their lower, stiffer suspension. In fact, given how good the standard suspension set-ups are, we wouldn’t pay for the expensive optional air suspension.
Four-wheel-drive A6s are also wonderfully stable in all weathers, although the front-wheel-drive ones are hardly wayward.
The S6 gets a more sophisticated four-wheel-drive system than other A6s, which helps it turn in to corners more keenly.
The only real criticism is the A6’s steering. Although it is precise and light enough around town, it doesn’t weight up sufficiently on faster roads or provide much information about how hard the front tyres are gripping.
Much like when it comes to ride comfort, a BMW 5 Series equipped with the optional variable shock absorber control rules the roost as far as handling is concerned. It handles more sharply than the A6 and its steering is more reassuring on twisty roads.
Audi A6 Saloon refinement
Superbly refined, especially the 2.0-litre diesel engine
This is an area that the A6’s rivals struggle with, particularly with their equivalent four-cylinder diesel engines. Audi has managed to abolish the diesel clatter from its four-cylinder 2.0-litre engine, though, even at high revs. You feel precious little vibration, too.
The 3.0-litre diesels are also smooth, but there’s more of a background grumble at idle and when pushed beyond 3000rpm. The noise isn’t intrusive, though, and the BiTDI sounds genuinely sporty. You’ll also hear the engine in the S6, but its V8 burble is exactly the sort of noise you’ll want to hear in a performance saloon.
Otherwise, there’s some wind noise on the motorway and a little road noise on coarse surfaces, especially on models with larger wheels, but, on the whole the A6 is a superbly refined car. In fact, it’s one of the quietest executive cars money can buy.
Most versions are fitted with a seven-speed S tronic automatic gearbox, which can be a little jerky at manoeuvring speeds, but is otherwise slick. The BiTDI gets an eight-speed automatic ’box, which is smooth at all speeds.
This is the engine to go for if you’re a company car driver or private buyer. It’s strong enough to haul a family and their luggage, and wonderfully smooth and refined at the same time. It’s impressively tax-efficient, too. It is the only engine in an A6 that’s available with a manual gearbox, although we’d pay the extra for the slick S tronic automatic. It’s also the only engine that cannot be combined with four-wheel drive.
3.0 TDI 218
This entry-level six-cylinder engine is stronger than the four-cylinder 2.0 TDI, and is still refined, but it brings bigger fuel and tax bills. If your diesel engine has to have more than four cylinders, though, this is the one to go for. An automatic gearbox is standard, and this engine can be had with front- or four-wheel drive.
3.0 TDI 272 quattro
It makes the A6 extremely quick, but doesn’t really make much sense next to the lower-powered version of this engine, which is still punchy enough. It comes with quattro four-wheel drive and an automatic gearbox.
3.0 BiTDI 320 quattro
With this blistering twin-turbo BiTDI engine fitted, the diesel A6 takes some beating for straight-line pace and noise. Unless this is paramount, though, we’d stick to the cheaper and more economical single-turbo 3.0-litre versions. An automatic gearbox and four-wheel drive are standard with this engine.
4.0 TFSI S6
The S6’s thumping great V8 petrol engine delivers massive performance. Unless you’re looking for a stonkingly fast A6, though, we’d stick to one of the diesels instead; the BiTDI isn’t much slower but is far more economical. The S6 gets four-wheel drive and an automatic gearbox as standard.