Maker: General Motors
|The symbol of "new GM" is ready for
the toughest test: market launch
In the past couple of
years, General Motors was most frequently associated with two words: Bankruptcy and Volt. More interesting, they usually
coexisted in the same sentence. The Volt was one of the few
projects kept running in full steam during the darkest days of GM. It
was the light in the tunnel. It gave hope to GM and, most important, a
good excuse for Uncle Sam to bailout the company. Volt has been used as
a symbol of the "new GM". Its high-tech, efficient and socially
responsible image is what GM wants to project to the whole
Ridiculously, Volt is not going to make money during its lifetime. Its
substantial development cost is impossible to be recouped by selling
only 10,000 copies in 2011 and 45,000 copies annually thereafter as
planned by GM. Its production cost – especially those Li-ion batteries
and dedicated hybrid power system – are equally staggering, resulting
in a price of US$41,000. That is double of a conventional car of this
size ! To sweeten the deal, Uncle Sam helps again with a federal
incentive of U$7500 per car. Still, its $33,500 net price is difficult
to compete with conventional cars, or to less extent Toyota Prius
($23,000 to $28,000 without incentives). Expect technology enthusiasts
environmentalists to be its main supporters.
|It looks sleek, but aerodynamic drag
is a disappointing 0.28.
Externally, the Volt doesn't look as special as Prius, or as
futuristic it wants you to believe. Its shape is more or less a
conventional C-segment hatchback, just a little more slippery. If not
the fake front grille, you can hardly tell it is a plug-in hybrid car.
GM tried to inject some sophistication to the design with fancy light
graphics and panda-style "eye shadows" below the side windows, though
their effect is limited. To add your disappointment, the Volt has a
drag coefficient of 0.28, not only poorer than Prius (0.25) but also
less slippery than conventional cars like Mercedes E-class (0.25). 14
years ago, GM achieved 0.19 with EV1. Time did not improve its
Inside, the cabin of Volt is far more unconventional. The LCD
instruments and milky white center console look as if come from a 1990s
Volvo concept car. The console is full of touch-sensitive buttons.
Unfortunately, its shiny hard plastic surfaces feel cheap, and the
small markings and light reflection make it a nightmare for ergonomics.
Rest of the cabin materials are hard grained plastics, hardly match
those in a modern supermini, let alone a car at this price. This
reflects the downside of its rush to the market and its low production
volume. On the upside, both LCD screens on the instrument pod and
center console displays well designed graphical information for the
hybrid power system, its state of power distribution, battery reserve
and estimated mileage etc. They are presented in an interactive way to
encourage you to drive as frugally as possible. That said, it's no more
attractive than the Powerball of Honda FCX Clarity.
|High on wow factor but short of space
The Volt shares the C-segment Delta platform with
Chevrolet Cruze (Daewoo Lacetti) as well as its 2685 mm wheelbase,
therefore don't expect Prius level of interior space. Its rear seats
are cramped for six-footers, while a prominent transmission tunnel
makes it strictly a 4-seater. Luggage utility, however, is good, thanks
to a hatchback door, large load bay and fold-flat rear seats.
The "transmission tunnel" runs the full length of the cabin because it
accommodates a large part of the Lithium-ion batteries. The
batteries are situated under the rear seat, forming a letter "T"
together with those in central tunnel. Needless to say, placing
200kg of batteries low in the floorpan and within the wheelbase help
improving center of gravity and balance of the car. However, part of
the balance is offset by the 1.4-liter petrol engine and large electric
motors up front, so the Volt is about as nose-heavy as conventional
front-wheel drive cars. Moreover, the large batteries and
hybrid powertrain also lifted its kerb weight to 1715 kg. That is 335
kg more than Prius !
However, direct comparison with the Toyota hybrid could be unfair
Volt is a plug-in hybrid. In the Toyota, as well as any other hybrid
cars on the market until now, engine is the primary source of power
while battery and electric motors work only during low speed cruising,
regenerative braking or provide assistance during acceleration. This
why the Toyota has only a 80hp motor and a 3kWh NiMH battery pack. It
can run on purely battery power for only 1 mile, and at a speed no more
than 25 mph. In contrast, the Volt has a 149 hp motor and a 16kWh
high-performance Li-ion battery. In pure EV mode it can run up to 100
mph and has a range of 25-50 miles (remark: during test drives most
journalists achieved 30-40 miles). This mean many people will be able
to drive to work and back home without ever firing the engine. To them,
Volt is equivalent to a pure electric car. All you need to do is just
to plug in the car
at your home socket and recharge it overnight. This takes 10 hours on
120V home socket, or 4 hours on special 240V socket. It goes
without saying that
electricity bill is a lot cheaper than fuel bill. Also, electricity
generation at power plant is far more efficient than burning gasoline
or diesel in your cars.
|T-shaped battery occupies the backbone
and underseat area.
Compare with electric cars, Volt has a strong advantage in
range. When its battery runs low, it turns on the 1.4-liter petrol
engine, which generates electricity to feed the motor. With a full tank
of fuel and full battery, the car has a range of more than 300 miles.
Moreover, it can refill at gas stations, so
there is no worry of running out of energy like EVs.
This sounds simple, but in reality the plug-in hybrid system is quite
complicated. It incorporates a 84hp Opel 1.4-liter engine, a 149hp main
motor, a 74hp auxiliary motor and a planetary-gear CVT. The main motor
is purely for propulsion, whereas the auxiliary motor primarily acts as
generator but may also be used as propulsion motor if needed. Both
motors are ring-shaped, and their cores are inserted with the planetary
gearset so to save space. Both motors may engage or disengage the
gearset via clutches. The engine, sits next to the auxiliary motor,
uses another clutch to engage the gearset through the auxiliary motor.
The control system has 4 modes of operation:
1. EV mode for low speed
(up to 70 mph): only the main motor is engaged, so all power
comes from the 149hp motor;
2. EV mode for high speed
(up to 100 mph): both motors are engaged to provide power. The
combined output is still regulated at 149hp, but running two motors at
lower rev is more energy efficient than running only the main motor at
3. Range extending mode
for low speed (up to 70 mph): when battery runs low, the engine
starts working. It drives the auxiliary motor, which now acts as
generator and is decoupled from the gearset, to generate electricity
and supply the main traction motor. As a result, the car is powered by
the main motor. Of course, the 84hp engine cannot generate enough power
to realize the main motor's 149hp output, so this mode works at below
70 mph. However, in case of overtaking or ascending, the combination of
engine power and battery reserve may still allow short burst of full
4. Range extending mode
for high speed (up to 100 mph): all clutches are engaged. This
mean the engine is mechanically connected to the gearset via the
auxiliary motor. The latter still works as generator to supply the main
traction motor. However, the majority output now comes from the engine.
Again, momentary release of full power is possible from the combination
of engine and battery power. For extended exploit, output should be no
more than the engine's 84hp. Still, this is enough to keep up with
traffic on highway.
||Voltec hybrid system is complicated
Nevertheless, the fouth mode means Volt is not exactly an
"extended range electric vehicle" as GM claimed, because its engine may
drive the wheels through mechanical means. A real extended range EV
shall have only electrical connection between the engine and the drive
system. This caused some debates in the press.
Anyway, forget the definitions and principles. The most we care is how
the Volt performs in the real world. The answer is quite positive.
The Volt is more refined than traditional hybrids like Prius. It is
free of engine noise and low on wind and road noise. In EV mode it is
as silent as ghost, even under acceleration. In range-extending mode,
its engine cuts in imperceptibly and remains quiet unless you push it
hard. Moreover, its refinement does not come in the price of
performance. With as much as 273 pound-foot of torque available right
from idle, it provides a solid stream of acceleration. 0-60 mph is
achieved in less than 9 seconds, a full second quicker than Prius.
In corners, the car is also more capable than its rival Prius. Its
Michelin low-rolling resistance tires are wider and grippier. Its
braking is more powerful, despite of its hefty weight. Chassis balance
and ride quality are just as good as conventional cars. The brake pedal
and steering are not as linear and natural as conventional ones, but
still better than the ones you found on Prius. However, no one would
confuse the Volt with a driver's car.
Will the Volt succeed ? No, it won't. As mentioned before, it is too
expensive for a small car and too costly to build, so it will be a
money loser throughout its lifetime. However, if GM keeps developing
the "Voltec" hybrid system and extend its usage to more vehicles, it
may get return on investment some day. Toyota spent 7 years before
profitable. Thanks to fast progressing battery technology and wider
public recognition these days, GM may take less time to do so. Overall,
the Volt is a brave and respectable effort, if still not a competitve
alternative to conventional cars.
above report was last updated on 3 Nov 2010. All Rights Reserved.
|Length / width / height
|Other engine features
|0-60 mph (sec)
|0-100 mph (sec)
/ 1438 mm
|AC electric motors +
range-extender inline-4 engine
|DOHC 16 valves
|149 hp (full power)
84 hp (engine)
72 hp (battery)
|100 mph (limited)
|8.4 (c) / 9.2* / 8.7**
|30.3* / 23.0**
tested by: *C&D, **MT
by Mark Wan @ AutoZine