17-11-2006
At its 2003 introduction, the X3 offered something no one else could—a luxury-compact with the versatility and all-road capability of a sport-utility, combined with the quality, performance and handling of a BMW. Compared to the large domestic and Japanese sport-utility vehicles then dominating the market, the X3 offered a smaller, more nimble, yet in many ways equally versatile alternative. The X3 also introduced drivers to xDrive, BMW’s “intelligent” all-wheel-drive
system that offers near-instantaneous torque apportioning with changing road conditions. Nothing else in its class came close, and the X3 quickly reached virtually the same sales figures as its larger, X5 sibling.
As with any BMW, improvements have made the X3 a moving target since its 2003 introduction. Originally offered in two guises—2.5i and 3.0i—the 6-cylinder X3 has gained in value and equipment since that intro. The popularity of the more-powerful 3.0i encouraged BMW to make it the sole X3 offering for 2006, while upgrades in equipment, such as a standard Panoramic moonroof and the no-cost choice of manual or automatic transmissions, have kept BMW’s smaller SAV® ahead of any competitors.
As with the 2006 X3, the 2007 lineup consists of a single model, now designated the X3 3.0si. The new designation indicates that the X3 now boasts an engine upgrade, in the form of the 3.0-liter 260 hp aluminum/magnesium Valvetronic inline-6. Complementing that engine is a new 6-speed STEPTRONIC automatic transmission, replacing the previous 5-speed as a no-cost option. A 6-speed manual remains standard, as the 2007 X3 retains its position as one of the only vehicles in its class to offer a manual transmission for serious driving enthusiasts.
With the new powertrain, the X3 3.0si is significantly quicker than the ’06 3.0i:
0-60 mph in 6.9 seconds with its 6-speed manual, or 7.1 seconds with its new 6-speed STEPTRONIC. That’s an improvement of 0.8 second with the automatic or 0.7 second with manual. Complementing the improved performance is a similar gain in fuel economy, as the new 3.0si carries an EPA estimate of 19 mpg City / 26 mpg Highway with the automatic, or 18 City / 26 Highway with manual. No other luxury-compact sport-utility can match those mileage and acceleration figures.
Accompanying the new powertrain are numerous interior and exterior revisions, including reworked front and rear styling, new standard and optional wheels, and richer interior materials. In addition to more power, a more refined interior, and an augmented standard equipment list, BMW’s new Ultimate Service program increases the X3’s inherent value as the premier compact Sports Activity Vehicle®. In addition, new options and package contents enable customers to tailor the X3 to their own preferences.
Despite the increase in power and efficiency, a new 6-speed STEPTRONIC and revised interior and exterior appearance, the X3 3.0si’s base price is up a modest $1,200 from ‘06. The new X3 3.0si carries an MSRP of $38,695, including destination charge.
More horsepower and torque,
courtesy of BMW’s aluminum/magnesium inline-6
The 2007 X3 3.0si boasts significant powertrain improvements, beginning with the new Valvetronic 3.0-liter aluminum/magnesium 6-cylinder. With 260 horsepower and 225 lb-ft. of torque on tap, the new X3 3.0si makes marked improvements in its 0-60 mph performance, and it remains one of the fastest 6-cylinder SUV’s in the segment—6.9 seconds with its 6-speed manual or 7.1 seconds with its new 6-speed STEPTRONIC automatic. BMW’s exclusive Valvetronic technology ensures that
the X3 not only provides exceptional acceleration, but excellent fuel economy as well. At 19 mpg City, 26 Highway, the ’07 X3 3.0si automatic betters the mileage from the ‘06 3.0i by more than 10 percent. With its manual transmission, the X3’s figures are nearly as impressive, at 18 City, 26 Highway.
Valvetronic manages the two conflicting demands of modern engines—more power and better economy—by taking a new approach to valve control. Valvetronic varies valve lift to a far greater degree than other variable-lift systems—so much, in fact, that it replaces the traditional engine throttle. Instead of a conventional throttle controlled by the accelerator pedal, engine breathing is controlled entirely by the valves themselves.
The Valvetronic mechanism acts on the intake valves, imposing an additional control element between the camshaft lobe and rocker arm for each cylinder, called an intermediate follower. Upon contact by the lobe, this follower actuates a finger-type rocker arm and, in turn, the valve. The follower’s pivot point is positioned by an eccentric shaft, rotated by a servo motor in response to the driver’s accelerator-pedal movements; this varies the valve lift.
Also new this year,
in a class where a 5-speed automatic transmission is the norm, the 2007 X3 becomes the only luxury compact sport-utility vehicle to offer not one but two 6-speed transmissions. Last year’s benchmark 6-speed manual—unique in the class—is joined this year by the superlative 6-speed STEPTRONIC automatic. This new automatic not only offers an additional gear ratio over the previous 5-speed, but it benefits from the same improvements found throughout the
BMW lineup, making this 6-speed STEPTRONIC quicker-shifting, more fuel efficient and more responsive than ever. As in previous years, this new STEPTRONIC is available as a no-cost option.
xDrive + Dynamic Stability Control + Dynamic Traction Control =
all-wheel-drive performance
Like other current BMW models with all-wheel drive, the X3 incorporates BMW’s advanced xDrive all-wheel drive and traction system. Moreover, the 2007 X3 3.0si becomes the first BMW SAV® to include Dynamic Traction Control as part of DSC. At the touch of a button, DTC waits for a higher threshold of wheel-slip before engaging DSC functions. This helps when starting off on loose snow, for example. It also offers the driving enthusiast another dimension of performance.
In order to ensure a high degree of stability and traction under all conditions, the xDrive all-wheel drive system, DSC and the engine management system are networked via Integrated Chassis Management. Working together, the systems will react to a loss of traction at any wheel by first utilizing xDrive to move traction to the front or rear axle as appropriate. Then, if necessary, DSC will work to help stabilize the vehicle.
Considering the front and rear wheels as two pairs, the rears always drive; the proportion of the total driving torque apportioned to the front pair at any given time depends upon the degree to which the multi-disc clutch is engaged (i.e. the engagement pressure exerted by the servo motor). As more torque is transferred to the front wheels, a smaller proportion goes to the rear. With full traction at all wheels, the maximum proportion to the front is 50%; in a situation where both rear wheels are on glaze ice and the fronts are getting traction, the proportion going to the rears can approach zero.
But xDrive does not optimize traction alone; it can also enhance handling characteristics, fostering both agility and stability on non-slippery as well as slippery road surfaces. Via the same type of logic DSC employs to recognize and correct for excessive over- or understeer, xDrive adjusts the front/rear torque split to avoid these tendencies. If undesirable oversteer is sensed, the multi-disc clutch is completely closed, sending the maximum possible torque to the front wheels. If excess understeer is detected, xDrive opens the multi-disc clutch completely, leaving no driving torque at the front wheels. All this occurs smoothly, with no overt indications to the driver; the driver merely enjoys optimum dynamics under a wide range of driving and road conditions.
In connection with all these adjustments to the front/rear torque split, it’s essential to note that xDrive makes them ultra-quickly; reaction times (from sensing to control actions) are so fast that it could almost be said that the system operates pro-actively.
BMW chassis engineering
also contributes to X3’s road abilities
xDrive and bad-road capability, however, aren’t the only factors in the X3’s unique blend of handling talents. First of all, as the foundation for all this road technology, the X3 has a highly rigid unitized body structure that not only stands up to the rigors of tough going, but also abets a quiet and vibration-free ride in the more usual exercises of driving on paved roads and streets.
Up front, the suspension system is an X3-only version of the double-pivot strut-type layout that also contributes to the excellent ride and handling of BMW’s new 3 Series Sedans, Coupes and Sports Wagon as well as all 5, 6 and 7 Series models. At the rear, the X3 employs an evolution of the multi-link suspension concept from the previous 3 Series Coupes – called Central Link – for the more rugged terrain to which X3s will sometimes be subjected.
Aluminum components help reduce unsprung weight and thus contribute to a relatively supple ride over rough surfaces: in the front suspension, the forward lower links; at the rear, the upper transverse links. There are of course front and rear anti-roll (stabilizer) bars, and a firmer suspension calibration is included with the optional Sport Package (see Options and accessories).
Continuing a BMW concept first seen in the M3 sports cars and since their debut extended to other Series, X3s have specific reinforcements that help maintain precise suspension movements: at the front, a large-area thrust plate that also serves as a skid plate; at the rear, dual diagonal braces. Both beef up the underbody area where the suspension subframes attach.
As on all current BMWs, steering is by rack and pinion with variable power assist. Standard is engine-speed-sensitive assist, which increases at very low engine speeds to reduce parking efforts. Optional Servotronic vehicle-speed-sensitive assist further reduces parking effort and provides a progressive diminution of assist with increasing vehicle speed.
X3 exterior: a revitalized interpretation
of the SAV® concept
Distinct changes to the front and rear provide a substantially freshened look for the 2007 X3. The front end includes slightly larger twin kidney grilles, relocated side marker lights and repositioned foglights. On models with Xenon Adaptive Headlights, the inner lamps include corona rings, which can also function as daytime running lights if the driver so chooses. Also new, the Adaptive Headlights option adds cornering lights. These are built-in to the foglamps to provide additional
illumination in low-speed (under 25 mph) maneuvers such as parking. At the rear, reconfigured taillights incorporate LED lamps for the Adaptive Brake Lights.
As in 2006, on standard models the body sides are accented by flexible, damage-resistant black surfaces around the wheelwells and along the rocker panels. The same duo-tone treatment extends to the areas below the front and rear bumpers. Sport Package-equipped vehicles again get body-color wheel arches, lower bumpers and rocker panels. Roof rails are standard, as is a roof spoiler that contributes to an excellent 0.35 aerodynamic drag coefficient. Electrically released, the one-piece
tailgate rises on gas struts to provide 6-ft. clearance for loading.
A cargo area that accommodates
X3 users’ active lifestyles
The X3 cargo hold reflects BMW’s characteristic attention to esthetics and function. Accommodating up to 71 cubic feet of “stuff,” it comes standard with a retractable cover, velour carpeting and side trim, left- and right-side lights as well as one in the tailgate, and an accessory electrical power outlet; longitudinal rails can be used to secure accessories such as the available two-bicycle rack. Concealed storage is provided in the cargo area’s right side; an
available cargo net can be positioned in different ways to separate cargo and seating areas.
Roomy, versatile
and appealing interior
The changes for 2007 complement an already outstanding interior in the X3, with well thought-out ergonomics, tasteful design and new materials, plus options to make it even more luxurious and accommodating. The new instrument panel includes an integrated hood above the instruments, which blends seamlessly into the upper dash. Climate, audio and ancillary controls are grouped attractively above and in the center console; the Premium Package now adds an auto-dimming mirror with digital
compass.
Durable and functional leatherette upholstery is standard, as is new Dark Ash wood trim, which accents the forward console and extends across the dash. Either Gray Poplar or Light Natural Poplar wood trim is optional at no extra cost. Soft touch paint adds a touch of elegance to the door pull cutouts, and the armrests are now wrapped in either standard leatherette or the newly optional Nevada leather. Further optional features and materials are described under Options and accessories.
Standard furnishings include 8-way power front seats and a memory system for the driver’s seat and exterior mirrors. For 2007, the X3 options list includes 16-way Comfort Seats, in addition to the previous 8-way power/ 2-way manual sport seats available in the Sport Package. The steering wheel is tilt/telescopically adjustable.
Storage space is generous: each front door has two lower bins, now both fully enclosed for more secure small-item storage. For front occupants, the center console includes an armrest and single cupholder; a retractable dash cupholder serves the front passenger. The rear of the console also includes the new auxiliary stereo input for an iPod or MP3 player, as well as the switches for the 3-stage heated rear seats on models with the Cold Weather Package. The console compartment accommodates an available 6-disc CD changer.
The rear-seat backrest is split 60/40, its two portions folding down to provide cargo- and people-carrying versatility. In the “60” portion, a folding center armrest includes two cupholders, storage space and the center head restraint.
Safety and security:
new active features complement
the X3’s extensive passive systems
Since its introduction, the X3 has offered the full gamut of safety systems, including BMW’s first use of a curtain type front and rear Head Protection System. The 2007 X3 complements these features with a further emphasis on active safety systems. Like the rest of BMW’s 2007 lineup, the X3’s DSC now includes a range of new braking features: Brake Drying, Brake Stand-by, Brake Fade Compensation and Start-off Assistant. These are in addition to the previously standard
Hill Descent Control, which has been a part of the X3’s DSC since its introduction.
Brake Drying comes into play any time the X3’s windshield wipers are functioning. At certain intervals, the brake pads are brought up to the disc surfaces, just close enough to wipe them free of any water build-up without causing any physical wear on the pads or rotors. The result dries the brakes to eliminate any delay in response when the pedal is depressed.
Brake Stand-by senses whenever the driver quickly lifts his foot off the accelerator, and anticipates any extreme braking by pre-loading the brake pads against the rotors. The result minimizes any lag in brake performance by providing instantaneous response when the brake pedal is pushed. Together with Dynamic Brake Control (which has been a part of DSC for years), Brake Stand-by can help reduce the X3’s response time in emergency braking.
Brake Fade Compensation ensures consistent braking under the high temperatures brought on by heavy usage, such as an extended downhill or repeated hard braking. Brake fade reduces the brakes’ effectiveness, making it necessary to apply more brake pressure at the pedal to maintain a given amount of deceleration. During hard use, Brake Fade Compensation increases the pressure in the hydraulic system as the brake temperature rises, so the system maintains a consistent pedal feel even during repeated hard stops.
Start-off Assistant comes into play when the X3 is stopped facing uphill. At that point, the brake system maintains pressure for one second after the driver releases the pedal. The brakes continue to keep the vehicle stopped long enough to allow the driver to accelerate smoothly without concern about the X3 rolling backward. In a sense, Start-off Assistant is the ideal complement to the existing Hill Descent Control, which removes the need for driver intervention on steep declines. When HDC is actuated by the push of a button on the center console, the X3 maintains a constant speed without requiring the driver to “ride the brakes.” Hill Descent Control has been standard on all BMW SAVs® since the original 2000 X5.
Another X3 feature is Dynamic Traction Control. When engaged via its own console-mounted button, DTC allows a slight delay before engaging traction control. The minor amount of wheel spin that results can be helpful in certain road conditions, such as deep snow or loose sand.
The enhanced DSC is the newest of the safety features on the 2007 X3 3.0si, all of which are designed to work in tandem with the X3’s existing passive safety systems. Both front-impact airbags, for example, are further developed to optimize their 2-stage, accident-severity-dependent deployment characteristics, inflated shape and interaction with surrounding surfaces and components. Front safety belts include automatic tensioners and force limiters. The standard-equipment Head Protection System for front and rear occupants is configured as a curtain-type system.
Other notable safety features and systems include:
Ultra-sensitive “satellite” side-impact sensors. By sensing pressure change within the door structure (rather than deformation), they signal for deployment early in a side impact, yet minimize the chance of an unwanted deployment.
Interlocking door anchoring system. This familiar BMW feature employs an aluminum reinforcing bar in each door to strengthen the body side. At the aft end of each diagonally positioned bar is a hook-like member that, in a serious side impact, hooks into the body as the door deforms. The system is designed so that after most impacts, elastic snap-back releases the hook and the doors can be opened.
Intelligent Safety and Information System (ISIS), an overall system for controlling the vehicle’s safety systems and devices. ISIS is a decentralized system, with an overall Safety Gateway Module (SGM) and seven subordinate control units, each with a microprocessor of its own. This multiplicity of units provides a redundancy that helps preserve system reliability even when portions of the system might be damaged by accident forces. In interaction with the main and subordinate units, ISIS employs fully 14 sensors, which together achieve remarkable “tailoring” of the deployment of airbags, Battery Safety Terminal and safety-belt tensioners to actual accident circumstances.
Supporting the sophisticated electronic control scheme itself, fiber-optic cables are not susceptible to extraneous electromagnetic disturbances. System software can be updated over the life of the vehicle.
Options and accessories:
a wide range available to personalize the X3
Along with the updates in standard equipment, the 2007 offers a revised array of options and packages to complement owners‘ active lifestyles.
Text and photos courtesy of BMW AG
