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Taking active and passive safety seriously |
Many auto enthusiasts question whether a sport-utility vehicle can ever
be made to handle like a sports car. But remember years ago when the same
question was asked of sedans? Then sports sedans came along, cars that
handled as well as or better than sports cars. More recently, some station
wagons have managed to handle as well as their sedan counterparts.
The design of a traditional body-on-frame, truck-based SUV almost
precludes it from ever becoming a great-handling vehicle. The answer is an
SUV with a unibody or monocoque construction. Since several manufacturers
have started producing such vehicles, poor-handling SUVs could become a
thing of the past. However, to true-blue SUV enthusiasts, these unibody
SUVs are not "real" trucks — which is why they are often
referred to as hybrid vehicles.
The thought of BMW producing an SUV has sent chills through many Bimmer
enthusiasts. How, they ask, could BMW, with its position as the
"ultimate driving machine," produce an SUV that meets the
criteria one expects of a BMW? The answer is, the X5 — a sport-activity
vehicle (SAV), as BMW likes to call it. First unveiled at the Detroit auto
show in January, the X5 looks like an SUV, but BMW has promised that it
will handle and perform like a BMW sedan.
It is not the first monocoque SUV on the market — the Lexus RX 300
and Jeep Grand Cherokee take those honors. But until now, the
best-handling SUVs have been hybrid vehicles, such as the Subaru Outback
and Forester, that are more akin to car-based vehicles.
Dropped
Secrets
"You'll be stunned by the handling," a BMW official says to
me privately as we sit in one of two buses full of journalists being
escorted ("no cameras allowed") to watch a crash test of an X5
at one of BMW’s well-hidden research facilities in Bavaria. Was it a
coincidence that an X5 prototype was seen being driven around the handling
course at the BMW test facility just as we went by? The prototype X5
certainly looked stable as it was flung through a series of curves at
about 50 mph by the test driver (who may or may not have been told that 50
eagle-eyed journalists were watching.)
The X5, to be built alongside the Z3, in South Carolina, goes on sale
in November in the United States. The 2.8-liter six-cylinder model will
cost "under $40,000" while the 4.4-liter V-8-powered model will
cost "under $50,000," according to BMW. Although the X5 is an
all-new model with a unique platform, it will use many suspension
components from the 7-Series, which obviously goes a long way to help its
handling capabilities.
An important part of the X5’s handling will also be the use of the
various electronic stabilizing systems, such as ASC (Automatic Stability
Control), DSC (Dynamic Stability Control), CBC (Cornering Brake Control),
DBC (Dynamic Brake Control), ADB (Automatic Differential Brake), HBA
(Hydraulic Brake Assistant), and HDC (Hill Descent Control). Many of these
are already found on the sedans while others are new to the X5. Although
no outsiders have yet been privileged enough to drive the X5, it does
appear that BMW is going to extra lengths to make sure the driving
characteristics will be worthy of a BMW and that active safety will be a
key component of the vehicle.
Passive
Safety
Passive safety also has been a major part of the development of the X5.
It has no less than eight airbags to protect occupants in a major crash.
Each font-seat occupant gets a front airbag, a side thorax airbag, and a
side headbag, while rear occupants (excepting the center seat) each get a
side thorax airbag. The airbag system is essentially the same as in the
7-Series models. BMW’s internal crash testing indicates that the X5 will
easily obtain a five-star rating in the NHTSA crash ratings, making it as
good as the best sedans. Overall, BMW claims it will set new safety
standards for this class of vehicle. "The X5 will be a benchmark for
safety in off-road vehicles," says Anton Wadenstorfer, a senior
safety engineer on the X5 project.
As continuing research into safety, BMW demonstrated the X5’s ability
to withstand a side impact into a pole at 20 mph in front of 50 or so
journalists from around the world. For many, this was the first time they
had witnessed an actual crash test. The driver’s door caved in
substantially, but the head and thorax side airbags cushioned the dummy’s
head sufficiently that, had it been a real person, he or she should have
survived the crash without serious injury. Side impacts are tough to
counteract, as there is almost no crumple zone to cushion the impact. BMW
also has taken into account potential damage caused to those outside the
vehicle by integrating lower bumpers so that the vehicle does less damage
to small cars in an accident.
Designworks, BMW’s design studio in California, created the exterior
look of the X5 while BMW engineers in Munich engineered the chassis.
Initially, the X5 will only be sold in the United States, where SUVs are
most popular. BMW is hoping that the handling of the X5 will be so good
that it will encourage more European buyers to consider an SUV — sorry,
an SAV — in the future.
by John Rettie
August 30, 1999
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