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SEVILLE, Spain — With prices starting at $11,590 for the basic Pure model,
the Smart Fortwo is one of the most economical rides in the States—even if
it's a long way from being the cheapest. The tiny, 70-hp Smart car was
introduced in the United States this January and has sold like wildfire
through Penske Automotive Group dealers. It's good for 90 mph and 0-60 mph
times around 12.8 seconds. No, it's not going to embarrass your neighbor's
AMG—unless you're competing for fuel economy, that is. The Smart delivered a
rather frugal 33 mpg city and 41 mpg highway in the 2008 EPA tests. And
that's not good enough, says Smart's parents at Mercedes-Benz, which
recently unveiled a trio of even more economical Smart cars. We recently
drove all three over here across the pond.
And maybe even better news: Mercedes-Benz's head honcho Dieter Zetsche
announced this week that the German company will sell an electric Smart for
2010, along with an electric Mercedes-branded vehicle. It's likely that both
will use lithium-ion battery technology. But 2010 seems like an awfully long
time to wait these days, so we slid behind the wheel of the first-gen Smart
EVs—part of a research project in conjunction with British electronic
specialists Zytek. Closer to reality is the new the micro-hybrid-drive
gasoline Smart with a stop/start system. It will be introduced into all
gasoline Smart models with the exception of the tuned-up Brabus version
(Europe only), beginning in September. The new Smart diesel will be
introduced in Europe this year, but probably won't make the jump over to the
States. —Andrew English
The EV
Based on the previous Smart model, over 100 of these battery-electric
vehicles have been converted in Fradley, Staffordshire and are on test all
over the UK. The 30kW/41hp brushless, liquid-cooled, DC motor is designed
and built by Zytek, with the motor, inverter and controlling electronics in
one housing. All that fits onto the conventional engine's three mounting
points. The conventional transmission is locked into second gear, as there's
no need for more given the torque delivery characteristics and 12,000-rpm
peak operating speed of the electric motor. The high-temperature salt
battery is a natrium-nickel chloride unit made by MES-DEA of Switzerland,
which is mounted under the floor where the fuel tank sits in a conventional
Smart.
Top speed is 75 mph and the 0-37 mph acceleration is quoted at 5.7sec, about
the same as that achievable with the petrol Smart. Maximum range (with very
gentle driving) is 70 miles. But you need to avoid fast acceleration and
hard braking to achieve this. Brake gently, and the kinetic energy is
recycled as electricity; brake hard, and the friction linings are brought
into play, wasting energy as useless heat. The battery can be recharged via
a conventional British 220/240 volt socket, and it takes eight hours for a
full charge from empty. But it takes three and a half hours to recoup from
30 to 80 percent of its capacity. On the European Combined cycle, power
consumption is about 12kW/hrs per 62 miles and at current values this costs
around 0.02 Euros per kilometre ($0.05 per mile). The battery can be
recharged at least 1,000 times, which in normal use gives a life of about 10
years. Currently, British firms are paying about $750 per month in leasing
costs to use these little cars—plus the recharging costs, of course.
Inside, the EV Smart is almost identical to its gas sister, although there's
only a two-position gearlever (Drive and Reverse). The charge-level
indicator is in the middle of the instrument binnacle. The battery remains
hot all the time, so starting takes no more than five seconds after a
systems check. Then you simply press the throttle and go.
The little car is quick off the mark as the traction motor delivers all of
its 88.5 lb.-ft. of torque to the rear wheels from zero revs. As a result,
it's difficult to maneuver in tight places as the car tends to surge
forward. You need to keep your left foot covering the brake. You also need
to keep your hand on the horn, as pedestrians don't hear the little Smart
coming and will step off the sidewalk right into its path—this is going to
be an ongoing problem for electric vehicles in built-up areas.
The standard Smart is hardly the acme of ride quality, and with 242 pounds
more weight, the electric version is worse. On smooth roads, this
electric-powered two seater is fine, but the individual wheel rates are high
and the wheels crash into pot holes and sleeping policeman. It's an
experience best forgotten. In addition, the electricity-powered air
conditioning system is, frankly, a joke.
On suburban roads, though, the electric Smart is a hoot. The limited top
speed never seems to be a problem, and there's always enough instant surge
to go to for the gaps. Of course, the emissions-free operation only applies
to the tail pipe, and fans of pure battery technology always seem to have a
blind spot about what lies beyond the plug and where the electricity comes
from, but for polluted city centers, the advantages of this silent-running
bollide are obvious—even if you end up driving around pedestrians like cones
on a slalom course.
The Diesel
In the European Combined economy tests, the standard Smart delivers 50.0 mpg
(US) and emits just 116 grams of carbon dioxide on the EU combined cycle.
Crikey, is it possible to save more fuel than that? Apparently so. Mercedes
is claiming the Smart fortwo CDI's 799cc three-cylinder engine is the
world's smallest direct-injection diesel, and that the CDI Smart is the
world's most economical series production vehicle. It's also the noisiest.
Compared to the previous oil-burning Smart, this new model has common-rail
fuel injection at higher pressures (up to 23,200 psi), new seven-hole fuel
injectors and a particulate filter that captures 40 percent of particulate
emissions. Power and torque are up 10 percent to 44 horsepower and 81 lb-ft
of torque respectively. Mercedes says it will deliver 71.3mpg (US) and emit
just 88g/km in the EU Combined cycle, which comfortably puts it at the
forefront of any list of production economy cars. In fact this little car
can do 621 miles on a brimmed tank, enough to travel the 1,200 miles between
the farthest points on mainland Britain with just one tank fill.
But there's a hitch.
You'll need earplugs. The car, particularly after a cold start, sounds like
a cement mixer on methanphetamine. That's from the sidewalk. From inside,
the well-insulated cabin is more tolerable. The noise isn't the only
disadvantage: top speed is 84mph and 0-62 mph takes nearly 20 seconds. So
the diesel Smart isn't going to set the world alight. But for off-the-line
bursts, it doesn't feel too bad.
The bête noir of the Smart range has always been its automated five-speed
gearbox. While this new model is better, the transmission still blunts the
performance by taking so long to swap ratios and occasionally disengaging
drive for seconds at a time. You see the traffic gaps open, you bury your
right foot and before the car has done anything, the gap closes again it's
very frustrating. The Obox is also programmed to rev out towards the 4,000
rpm redline more strongly than suits the engine's torque curve. On occasions
it might be better to short shift manually and let the torque do the work.
In the end, however, you do learn to make reasonable progress in the diesel
Smart by never lifting off, looking as far down the road as possible and
anticipating traffic flows to avoid using the brakes.
This latest-model Smart is vastly improved over its predecessor, which was
never sold in the US. The trunk has a proper external release, the door
mirrors are now big enough to let you spot stuff smaller than a truck behind
you and the facia is better made and less toy like. The cabin is more than
big enough for two large adults and the trunk will take a couple of small
suitcases. The car is also a great deal more stable at freeway speeds,
although it still feels top heavy in corners and the brakes are overly
sharp. The two-seat cabin also restricts its practicality and makes this
something of an urban eco toy for the wealthy middle classes and their
nannies. When we get the diesel here in Britain, it will cost about $1,300
more than the standard gasoline model. And unfortunately, we'll not get the
new start/stop function that comes to all gas models this September.
You do suffer for the diesel and not just in the sticker price. It's slower,
a lot less refined and downright noisy. The upside is the fuel consumption.
Over here, diesel costs about $10 a (US) gallon at the moment. A diesel
Smart returning this sort of fuel economy is pretty much immune from the
effects of the oil-price crisis, which leaves you lots of spare money to buy
a nice pair of Bose noise-canceling headphones for when you're in the car—or
a high-tech hearing aid for when you leave it.
The Micro Hybrid Drive
The Micro Hybrid Drive (MHD) isn't a hybrid in the accepted sense of the
word. The drive doesn't "drive" the car, and doesn't power the air
conditioning. This "hybrid" unit is a beefed-up, belt-driven
alternator/starter, which simply powers the stop/start function by
recharging the battery on over-run and restarting the car quickly. The 70
horsepower, one-liter gas engine cuts out as the car rolls to a stop at
under 5mph. And it automatically starts again as soon as you take your foot
off the brake pedal.
It's a simple system that has a big fuel consumption benefit. Mercedes
reckons the MHD Smart will return 54.7 mpg (US) in the EU Combined cycle,
which is an eight percent improvement. Fuel savings could be as high as 19
percent in crowded city streets. In use, it's almost pain-free. Restarting
involves a little more noise and vibration than the equivalent system on
BMW's bigger diesel MINI. This is not such a bad thing, however, as there is
at least the confidence that the engine is actually running when the lights
change and you put your foot on the throttle.
The system will be fitted to all non-diesel Smarts from September this year,
although the company is vague as to whether US Smarts will get the drive
immediately.
We hope they do: it seems like such an eco no brainer. Just imagine if every
engine in Los Angeles was stopped as soon as its speed dropped below 5 mph.
What would that do for fuel consumption? Or air-born particulate emissions?
How much sweeter the air would be, how much quieter the sidewalk.
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