|
Chevrolet Impala
Debut: 2005
Maker: General Motors
Predecessor: Chevrolet Impala (1999)
|
|
 Last
year, Chevrolet sold 290,000 Impalas in the America, making it the
third largest selling car in the category just behind Toyota Camry and
Honda Accord. The selling points of the car are mainly low price and
practicality. However, as the even cheaper new Hyundai Sonata entered
the scene, Impala may not retain the same sales result this year, even
with the revision introduced in 2005.
The revision concentrates on 3 areas: 1) facelift, 2) new engines, 3)
minor tuning and stiffening. The facelift is quite pleasing. It
reshaped the nose and tail to look sleeker and smarter than the
dull-looking old car. And then the front end structure is stiffened,
the engine mounts improved and the suspension setup retuned to reduce
noise and vibration. The result is a 50 kg increase of weight. The
steering is also retuned to improve response and feel, though it will
never be regarded as a driver's car.
Impala now adopts the new generation 3.5 and 3.9-litre V6s from Pontiac
G6. Though both engines still employ push-rods ohv, 2 valves per
cylinder and a heavy cast-iron block, they have a variable cam phasing
system to improve efficiency. Power output is 210 hp and 240 hp
respectively, considerably higher than the old 3.4 V6's 180 hp and 3.8
V6's 200 hp yet drink less fuel. However, while power matches that of
the Japanese and Korean rivals, their smoothness and eagerness still
lag behind the world standard.
Surprisingly, Chevrolet Impala re-introduces the SS badge with a new
small-block 5.3-litre V8, codenamed LS4. The pushrod V8 pumps out a
respectable 303 horsepower and 323 lbft of torque. It also has DOD
(Displacement On Demand) function, which can shut down 4 cylinders to
save fuel when the engine is running at light load. Even mated with a
4-speed automatic (compulsory on all Impalas actually), the V8 can push
the 1682 kg car from rest to 60 mph in 5.7 seconds. This might match
the slightly more powerful and slightly heavier Chrysler 300C, but
don't forget the Chevy Impala SS is a front-drive car with all
MacPherson-strut suspensions. That means horrible torque steer. The
addition of V8 is more an advertising tactic than a call from keen
drivers, who had all bought a Chrysler 300C, Dodge Magnum or Dodge
Charger.
However, to comfort-seeking buyers, the Impala is quite satisfying. The
Impala is always a big car with longer than average wheelbase. That is
an inherent advantage to ride quality. Now with additional NVH
suppression works, the cabin becomes remarkably quiet and the ride is
pretty refined. The cabin also received a lift in materials and trim
quality, plus more comfortable seats. In this way, most of the
weaknesses of the original Impala has been sorted out.
The Impala is by no means outstanding, but it is not a bad car either.
For those who care price and practicality more than image and driving
pleasure, it is still a reasonable choice. |
| The
above report was last updated on 4 Sep 2005. All
Rights Reserved. |
Impala SS
|
 While
you think the 268hp Camry or the 265hp new Altima the most powerful
family sedans you can buy in the America, GM is putting a
303-horsepower, 323 lbft 5.3-litre V8 into the engine bay of Chevrolet
Impala SS. Yes, it is the same “small block” push-rod V8 as last year’s
Pontiac Grand Prix GXP. It wants to use astonishing grunt and
tire-smoking acceleration to lure Americans back to the domestic brand.
The Empire strikes back !
Patriots, don’t get excited so early. Although there is nothing wrong
with the engine (apart from a little thirsty), the chassis fails to
cope with the extra power and torque. The outdated W platform is not a
good basis for a performance car. How can its front wheels, suspended
by MacPherson struts, withstand the torque from a V8 engine ?
especially when there is neither limited slip differential nor
equal-length half shafts to relieve the torque steer ! and how to deal
with wheelspin ? a traction control applies brake to the spinning front
wheel, so the engine power shift discreetly from one wheel to another,
ruining the steering.
You might remember Pontiac Grand Prix GXP employs
wider tires up front than the rear to reduce understeer and a set of
specially developed Bridgestone with stiffer sidewall to reduce torque
steer. They work quite well in the Pontiac. Unfortunately, Chevrolet
Impala SS gets none of these. Not just that, it even increased the
final drive ratio from 2.93:1 to 3.29:1 in the attempt to improve
acceleration further. This amplifies the torque steer and wheelspin
problem. I think its project manager must be either ignorant or mad.
 Another
problem is the lack of suspension upgrade. The soft tuning leads to
plenty of body roll and pitch to ruin any confidence. By the standard
of fast-going family sedans its handling is already poor enough, let
alone rear-drive rivals like Chrysler 300C. Other aspects are no
better, ranging from the boring 4-speed automatic gearbox (still no
manual mode) to the dull steering. The Impala SS must be developed at a
very tight budget.
The only merit is the V8 engine. You can enjoy its lovely rumble-bumble
and streams of torque on highway. If you can find a straight long
enough, you can experience very strong acceleration too. But this
talent is too limited. The bottom line is: GM has put a good engine
into a wrong car. |
| The
above report was last updated on 12 May
2006. All Rights Reserved. |
|
|