The engine may be ‘only’ four liters,
but tell that to the semi-conscious Labrador in the back. They’ve ditched the
V10, but this is still the wildest way to get luggage round fast corners.
Audi was never going to top the last RS6 –
short of supercharging the Aventador’s 6.5-litre V12 or giving the Veyron’s
quad-turbo W16 a second home. A Lamborghini-derived V10 (in cahoots with two
turbos) made it the most powerful road car the company had ever built and five
years on that still remains the case because the new RS6 has less power than
its ferocious predecessor.
Not that this Mk3 über-Avant is to be found
wanting: downsizing means it’s got the smallest engine ever fitted into an RS6,
but it’s still a twin-turbo 4.0-litre V8. It’s the same base motor you’ll find
in Audi’s S6, S7 and S8 – and the V8 version of the Bentley Continental GT –
and with both turbos and the intercooler between the ‘V’ it’s compact enough to
sit entirely ahead of the front axle in Audi tradition.
In those other Audis and Bentleys the
bi-turbo V8 produces between 309kW and 382kW, and 550Nm and 660Nm, but Quattro
GmbH (the Audi equivalent of BMW M or Mercedes AMG) has tuned the RS6 to 412kW
and 699Nm. Those aren’t peaky outputs either: the torque curve is fatter than
Table Mountain, and that BMW M5-equalling power is produced across nearly one
thousand revs. The new V8 is 15kW down on the old V10, but 50Nm up – not bad
given the loss of a whole liter’s worth of engine capacity and while there’s no
RS6 saloon this time, the same drivetrain powers the new RS7 Sportback.
Under
light loads and low engine speeds the intake and exhaust valves of cylinders
two, three, five and eight shut down, which reduces consumption by around 5%
Official figures of 9.8ℓ/100km and 229g/km
CO2 won’t see the RS6 escape the emissions tax, but they’re 40% improvements
compared with the 14.1ℓ/100km and 333g/km of the old V10. Two fewer cylinders
helps, as does stop/start, and the VW Group’s cylinder-on-demand (COD) system.
Under light loads and low engine speeds the intake and exhaust valves of
cylinders two, three, five and eight shut down, which reduces consumption by
around 5%. And active engine mounts counter the vibrations, so even with rapt concentration
you never know when the V8 is a 2.0-litre four-cylinder.
Establishing that the COD tech works
brilliantly, we went on to average 25ℓ/100km, reasoning you’d also want to know
what it’s like to ride in a two-ton estate as it hits 100kph in under four
seconds. There’s probably a few-tenths difference between using launch control
or just leaving the gearbox in D and stamping on the throttle, but either
method will see the family Labrador concussed by the rear window and squabbling
children go quiet. An M5 or Mercedes E63 will stutter as traction control
fights to save the rear tires or unchecked the torque will smear two black
lines onto the road instead but the RS6’s four-wheel drive means all the energy
is converted into instant momentum.
Typically
top quality interior mated to massive boot makes RS6 a better space than a
one-bedroom flat
Let the gearbox take care of the shifts and
there’s little fuss. But choose the DIY method and you need to concentrate: in
Manual mode the ’box never automatically upshifts, the first few gears are
short, and the acceleration is so ferocious that you can easily hit the
limiter. In first you need to be pulling the right-hand paddle almost as soon
as your left foot has sidestepped the brake, and although there are shift
lights in the head-up display to help (five bars that sequentially turn green,
then flash red) your reaction times won’t be quick enough. You’ll probably hit
the limiter in second too – the eight-speed auto doesn’t shift as quickly as
the twin-clutch ’box in the M5.
