Parkers overall rating: 4.8 out of 5 4.8
  • Appealing selection of petrol and diesel engines 
  • Performance diesel S6 available for those after torque
  • Plug-in hybrid added later

Entry-level models - branded 40 TDI - use a 204hp 2.0-litre diesel, which is mated to a seven-speed dual-clutch automatic and is available with either front- or Quattro all-wheel drive. This is our choice of the line-up with more than enough power for most drivers, yet is quiet and refined on the move. 

The most powerful standard diesel uses a 3.0-litre V6 unit, with the 50 TDI producing 286hp. This engine is available in all-wheel drive form only and is connected to an eight-speed automatic. Its appeal is slightly limited by higher fuel economy and a much higher purchase price, but it's a beautifully smooth and refined engine. 

Petrol engines kick off with the 45 TFSI, which uses a 2.0-litre four cylinder to produce 245hp. This comes with all-wheel drive and and a seven-speed automatic, taking 6.0-seconds to complete the 0-62mph acceleration benchmark. The top-of-the-range petrol is a 3.0-litre V6 that’s good for 340hp and, like the base diesel offering, uses a seven-speed dual-clutch gearbox for better performance. It's more difficult to make a case for this one, as it's effectively a halfway house to the S6. While it's very powerful, it's actually best enjoyed at lower speeds to make the most of the superior refinement.

The mild-hybrid system (12-volt for the 40 TDI, 48-volt for the rest of the range) allows the A6 Saloon to coast between 34 and 99mph (when the accelerator isn't being pressed) for that extra bit of fuel-saving, and allows the start-stop system to kill and quickly re-engage the engine smoothly.

If you want to be even more environmentally friendly then there's the A6 55 TFSI e, a plug-in hybrid with power and economy at its core. This will be available to customers in early 2020.

Audi S6 Saloon

At the top of the range (for now at least) is the diesel-powered S6 - an unusual but not unprecedented choice of fuel, given the fact Audi uses a diesel engine in the SQ7 and the previous SQ5 models too. This engine also powers the S6 Avant and S7 Sportback and is largely the same 3.0-litre V6 as you'll find in the 50 TDI, although with substantial reinforcements internally, plus a more powerful oil pump and injectors.

You get the same 48v mild-hybrid system, which charges up a lithium ion battery in the boot to allow for 40 seconds engine free coasting, but the real headline is the use of a 7kW electric supercharger this subsystem powers. This clever tech boosts engine responsiveness and provides power at the low end of the rev range for a sensation of bottomless power.

Consequently it feels very fast indeed. Still, it's 100hp less powerful that the old V8 petrol S6 and half a second slower from 0-62mph - although the 5.0-seconds this car takes is hardly slow. In fact it feels very fast indeed thanks to 349hp and 700Nm of torque that seem instantly available no matter what gear you're in.

As a result the S6 has a unique character among its rivals, with effortless, drama-free power for those who don't want to shout about it.

How does it handle?

  • Neat and tidy handling for a big car
  • Errs on the side of comfort than sportiness
  • Ride is far better than Audis of old

Sport models have the option of either standard steel sprung suspension or electronically controlled adaptive damping that works very well, absorbing bumps as well as any other car in the sector in Comfort (though we found the steering too light in this drive mode), and eradicating excess bodyroll in Sport.

However, on S Line cars confusingly you’ve got two different options. Standard-fit is 10mm lower than the Sport set-up mentioned above, and by rights should be firmer, but we tried this and were highly impressed with its performance on the sometimes terribly surfaced roads we drove it on.

Forget the old-school S Line suspension with its spine-crumbling ride; the latest effort is an impressive compromise between comfort and handling. We’d stick with this if ordering an S Line.

That’s because the other option is an air spring set-up and while the gulf between Comfort and Dynamic felt the widest of all configurations, in Comfort there was a slightly unsettled ride common to many similar air set-ups. Small imperfections create a shimmy through the car that never seems to stop, and we reckon after 100 miles or so it could become very tiring.

The low-speed ride is impressive, however, so if you’re buying an A6 for predominantly lower-speed driving then it could still be a decent box to tick.

We were very impressed with the way Audi has managed to engineer the rear-wheel steering, though. In some cars this sort of system can feel very unnatural or at times counter-intuitive, but in this case it’s cleverly judged. At lower speeds it means the A6 has a turning circle only slightly larger than an A3 because the back wheels can steer in the opposite direction to the fronts.

Go quicker and you’ll notice extra stability and thus confidence because those rear wheels turn with the fronts. It was only during second and third gear hairpin corners where we actually noticed much difference at all in the way the car handles: it feels a little like the engine accelerates mid-bend because your cornering speed increases quicker than expected. You’ll have to really concentrate to notice that, though.

S6's slightly sharper handling

While this car is undoubtedly a performance version of the A6 it's really more about the engine, so don't expect a nuts a bolts rebuild when it comes to the chassis and handling. Still, a useful 10mm drop and the availability of a Quattro sport differential keep things entertaining, in the typical Audi style of monstrous grip in bends.

Also available as an option are carbon ceramic brakes, which help haul the A6's bulk up quickly and reliably time after time, but are really only necessary if you plan on conducting repeated hard stops in your A6 Saloon with any sort of regularity.