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By MURRAY
HUBBARD
1 June 2009
It's a sign of the times. Audi's kick-butt S4 has gone from
a 4.2-litre V8 to a 3.0-litre supercharged V6. But has it gone
wimpish?
No way. The V6 is even quicker than the V8, and as a bonus the new
S4 gets almost 25 per cent better fuel economy.
What is missing is the V8 burble. What's not missing is the rest
of the S4's sporty DNA. Not since the heady Auto Union days of the
mid-1930s has Audi boasted a supercharged car. Back then they were
superb racers, now they are stunning road cars.
The 3.0-litre 245 kW V6 supercharged engine replaces the 4.2-litre
253 kW V8 in the previous S4. But the V6 has more of what really
matters, with 440 Nm of torque, easily outshining the superseded
V8's 410 Nm.
The new S4, just launched in Australia, is faster than the old to
100 km/h at 5.3 seconds - half a second quicker than the V8.
The engine has direct fuel injection and mechanical supercharging
using an Eaton Corporation Roots-style system ... much the same as
the old Auto Union racers in that respect. However, Eaton has been
able to develop a system that is more fuel efficient than early
Roots systems. “Extensive testing on the big V6 has proven the
superiority of mechanical charging,” said an Audi spokesman.
The compressor fits inside the 90 degree V of the cylinder banks,
in place of an intake manifold. Maximum torque hits at 2500 rpm
and goes right through to 4850 rpm. In conjunction with direct
injection is it far superior to twin turbochargers, both in terms
of packaging and of starting performance and responsiveness.
Power is put to the ground via Audi's-all-wheel drive quattro
system. While the change in engine is the most notable alteration
to the S4, it is not the only improvement.
The new S4 features a five-link front axle and self-tracking
trapezoidal-link rear axle made almost entirely of aluminium. It
now has low-mounted steering gear that sends the steering force to
the wheels without any lag time, giving the driver a more precise
road feel for the car. Stiffer shock absorbers put the car 20 mm
closer to the ground.
The S4 has also gone higher-tech with Audi's select driving
dynamics system. This allows the driver to choose between
‘comfort', ‘auto’ and `dynamic' settings that operate on the
throttle response, shift points for the S-Tronic, and steering.
It's a press button system.
It also comes with optional extras for those who take their
motoring seriously. Buyers can choose between adaptive dampers or
a sport differential, adaptive control for the shock absorbers and
with dynamic steering. The system reduces the load on the ESP in
high-speed cornering and stabilises the car through lightning-fast
steering interventions. This is not for your average punter as it
only comes into play when the car is at its handling limits.
Audi claims the active sports differential elevates the road
dynamics of the quattro car to a new level. Like a centre
differential lock which distributes torque between the front and
rear wheels, the active sport lock operates laterally on the rear
wheels. It can divert virtually all torque to just one of the
wheels, pushing it in the same direction as the steering wheel.
This helps the driver send the car in the direction he wants. The
result is quicker turning into corners and the benefit of
longer-lasting directional stability.
Visually, the S4 is impressive. Audi have continued with the
now-familiar xenon plus headlights with LED daytime running lights
and rear LED lights. These give the car a distinctive daytime
appearance.
The new Audi S4 is finished as a visually attractive sports
package, with 18-inch alloy wheels, sill panels, subtle rear
spoiler and a not-so-subtle quadruple exhaust system, that looks
like it should belong to a V8. What is somewhat bemusing is the V6
T badge on the front mudguards.
The interior continues the sporty flavour with sports seats
featuring electric lumbar support and pull-out thigh support,
instrument panel with grey dials and white needles and
multi-function steering wheel along with `S' emblems.
On our initial drive of the new Audi at the official press launch
we really missed the V8 burble. The unmistakable sound of a V8
with the pedal to the metal is something special to the keen
driver. We also wonder if S4 buyers will also mourn the loss of
the V8. If you can afford an S4, then the extra hit in the wallet
of three litres every 100 kilometres for the V8, will not matter
one hoot. Then again, that's a comment that’s not politically
correct for these times.
The V6 emits a hiss and a small `pop' as the seven-speed S-Tronic
dual-clutch shifter struts its stuff in what seems milliseconds
between gearshifts. It develops an engine note not dissimilar to a
straight-six engine and in its own way that's no bad thing.
Overtaking is a sensation with the Audi S4 rocketing from 80 km/h
to 120 km/h in a mere 4.4 seconds. Out, past and back in a blink
of an eye. We like it.
This fast Audi points beautifully, although we did not get to
drive the cars with the sport differential during the press
launch. Hopefully we can catch up with it later on our home
territory.
The Audi's ride is excellent for a car with this degree of
sporting prowess. On uneven tar is composed and river feedback
excellent.
© Copyright
Marque Publishing Company
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