The new xDrive system: variable torque split, quick reflexes in adapting to changing driving conditions
1 - According to Society of Automotive Engineers (SAE) standard J1100.
2 - "Auto Bild" is the parent magazine's name; "alles allrad" means "all about all-wheel-drive vehicles."
3 - VANOS = VAriable NOckenwellen Steuerung = variable camshaft control, or variable valve timing.
THE ALL-NEW X3
Woodcliff Lake, New Jersey, November 12, 2003... Four years ago, when it first launched the X5 Sports Activity Vehicle,
BMW began its foray into the luxury-SUV market; it was seen as a bold move. In fact, the X5 has been so successful that it has helped to spur significant growth in the luxury SUV market, which has more than doubled since the X5's introduction. Today, increasing X5 sales have required expanding the capacity of the plant at Spartanburg, SC, just to keep up with the brisk worldwide demand. The X5 has clearly proven itself, with a six-figure production volume over its first four years and accolades like these:
In the midst of this success story, BMW was busy developing a second, somewhat more compact Sports Activity Vehicle (SAV) that would -
This new vehicle is the BMW X3.
Overview: compact - yet roomy, practical and above all a thoroughbred BMW
For an overall perspective on the new X3, consider this comparison of dimensions and weights:
Thus the X3's exterior dimensions are not dramatically different, nor is the total interior and cargo volume - though the X5 does remain the roomier SAV. Yet the X3's more than 600-pound lighter weight signals its different position, as do its base prices; and the X3 is powered exclusively by 6-cylinder engines whereas the X5 is offered with both 6-cylinder and V-8 power. The new SAV is offered in two models: X3 2.5i, powered by the famously smooth and sonorous 2.5-liter inline 6-cylinder engine of 184 hp and base-priced at $30,995 including destination charge; and the X3 3.0i, with 3.0-liter/225-hp engine and a significant upward increment of standard features at $36,995. These prices lie exactly $10,000 (X3 2.5i vs. X5 3.0i) and $15,200 (X3 3.0i vs. X5 4.4i) below the two current X5 models.
Both X3 models come standard with a 6-speed manual transmission and are offered with an optional 5-speed automatic; both also embody the remarkable new xDrive all-wheel drive and traction system that the freshened '04 X5 Series incorporates.
Legendary BMW 6-cylinder power
BMW 6-cylinder engines are of the inline variety - a rarity these days as most vehicle makers have adopted V-6s, primarily because their compactness suits them well for tightly packaged front-wheel-drive cars. BMW stays with the somewhat longer inline layout because of its smoothness and sound, and indeed the expert media consistently applaud the Bavarians for doing so. In its first drive of the X3, the German magazine Auto Bild alles allrad 2 noted of an X3 3.0i with automatic transmission that "Even when one doesn't select the Sport mode, the smooth inline engine revs handily to its redline before the transmission shifts smoothly to the next gear." Both X3 engines share BMW's M54 engine architecture, whose salient points include -
The X3 2.5i's 2.5-liter version produces 184 hp @ 6000 rpm and 175 lb-ft. of torque @ 3500 rpm; it powers this model to a 0-60-mph time of 8.6 seconds with the 6-speed manual transmission and 9.3 sec. with the 5-speed automatic and maximum speed is electronically limited to 129 mph. The upper X3 3.0i model gets the 3.0-liter version, with 225 hp @ 5900 rpm and 214 lb-ft. @ 3500; it delivers a decidedly lively 0-60 time of 7.6 sec. with manual transmission, 7.9 sec. with automatic. Recently developed, the ZF Type H 6-speed manual transmission is notable for its light weight and precise shifting; it truly provides a gear for every driving situation. The 5-speed automatic is a STEPTRONIC, with Sport and Manual modes, the latter offering driver-controlled shifting by "flicking" the lever forward or rearward.
The new xDrive system: variable torque split, quick reflexes in adapting to changing driving conditions
Like the 2004 X5, the X3 incorporates BMW's all-new, intriguingly advanced xDrive all-wheel drive and traction system. Indeed, in the X3, along with its essentially all-new chassis, xDrive is at the heart of what are remarkable handling and traction capabilities. Housed in a transfer case behind the transmission, xDrive takes a new approach to apportioning driving torque between the front and rear wheels. In its essence, xDrive operates as follows:
Considering the front and rear wheels as two pairs, the rears always drive; the proportion of the total driving torque transferred 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 fronts can approach 100%. All-wheel drive is essentially permanent; however, under normal traction conditions, there are defined circumstances under which xDrive operates in rear-wheel drive only:
In normal driving, the clutch is operated with minimum slip, resulting in a torque split of 40% front / 60% rear. Under conditions of uneven traction, the control system interprets wheel-speed data to determine the front/rear driving-torque proportions; additionally, the DSC traction-control function can intervene to reduce engine torque and apply individual wheel brakes, thus assisting in achieving the maximum possible usable drive for moving the vehicle. Via the DSC switch on the console, the driver can also de-activate engine intervention, leaving only the brakes; this function is referred to as ADB-X (Automatic Differential Brake for all-wheel drive).
But xDrive does not optimize traction alone; it can also optimize handling characteristics, enhancing 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 without any overt indications to the driver; the driver merely enjoys optimum vehicle dynamics under a wide range of driving and road conditions. xDrive even varies the front/rear torque split according to acceleration on dry pavement, increasing the proportion to the rear wheels under heavier acceleration and decreasing it under lighter acceleration. The system's algorithms are programmed to accomplish this.
In connection with all these adjustments to the front/rear torque split, it's essential to note that xDrive makes them ultra-fast; reaction times (from sensing to control actions) have been reduced so much that it could almost be said that the system operates pro-actively. At the "bottom line," xDrive deals optimally with a wide spectrum of traction conditions. More remarkably, the system also optimizes vehicle dynamics or, more popularly expressed, handling; it enables the X3 to offer what is surely the most agile handling characteristics ever achieved in this vehicle format. Auto Bild alles Allrad again: "The new xDrive system makes a convincing debut. Given adequate wheel loading, on vigorous runs at steep unpaved hills there's no noticeable wheelspin." And the German magazine noted what it called "satisfactory measurements for this type of vehicle" for ground clearance, fording ability, and approach/departure angles.
BMW chassis engineering also contributes to X3's road abilities
xDrive and bad-road capability, however, aren't the only factor in the X3's unique blend of 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 fosters a quiet and vibration-free ride in the more usual exercises of driving on paved roads and streets. Up front, the suspension system is a new, X3-only version of the unique double-pivot strut-type layout that contributes to the excellent ride and handling of BMW 7, 5 and X5 Series models. At the rear, BMW has developed the multi-link suspension concept from the 3 Series - called Central Link - for the more rugged terrain to which X3s will sometimes be subjected. At both ends, 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 both models' optional Sport Package. Continuing a BMW concept first seen in the M3 sports cars and extended to other Series since their debut, all 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; and 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. The X3 is the first BMW Series to offer Servotronic vehicle-speed-sensitive assist as a stand-alone option: This system has the benefit of further reducing parking effort and providing a progressive diminution of assist with increasing vehicle speed.
Four-wheel ventilated disc brakes are standard, with massive 12.8-in. / 325-mm diameter rotors at the front and 12.6-in. / 320-mm at the rear. Five alloy wheel types are offered:
Once again we allow that German magazine Auto Bild alles allrad to provide independent verification of the overall results of BMW's efforts: "The X3 follows the commands of its very direct steering; there's no sluggish understeer. In fast curves, the body rolls hardly at all; the X3 maneuvers smoothly and securely on poorly surfaced mountain roads. On slippery asphalt, the xDrive's stabilizing effect is confirmed: handling remains nicely neutral, and the sport-calibrated DSC seldom needs to intervene." Another German magazine, Auto Zeitung, concurs in its October 22, '03 issue: "Foolproof and sporty handling...Even more dynamic is the X3 with sport suspension and the differentiated front/rear tires; many sport sedans won't be able to keep up with it."
Dynamic Stability control with trailer stability function
As in other current BMW models, a full-function Dynamic Stability Control system is part of every X3; this includes electronic brake-force proportioning, antilock braking, specific wheel-brake action to promote stability when braking and cornering take place at the same time, and Hill Descent Control to assist the driver in regulating the vehicle's speed on steep downhill runs. On the X3 and X5, DSC adds a function that helps prevent control difficulties with a trailer in tow. Should the trailer begin to become unstable, DSC intervenes to help stabilize it. Trailer-towing equipment is a BMW Center-installed accessory.
X3 exterior: fresh interpretation of the BMW SAV esthetic
A look at the X3 from any angle reveals a visual expression of the engineering concept: this SAV fairly radiates agility, grace and athletic youthfulness. One sees the concave/convex interplay that characterizes all recent BMW designs. Clean body sides are accented by flexible, damage-resistant black surfaces on the bumpers' impact surfaces, around the wheelwells and along the rocker panels. Roof rails are standard, as is a roof spoiler that helps the X3 achieve its 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 typical 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; in the 3.0i model and as part of the 2.5i Premium Package, 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 X3 cabin is BMW through and through: well thought-out ergonomics, tasteful design, materials and equipment that range from efficient quality (standard-equipped 2.5i) to elegant luxury (with available leather and optional trim materials). Climate, audio and ancillary controls are grouped attractively above and in the center console; durable and functional leatherette upholstery is standard, accented by Slate Gray console trim, door pulls and door handles. In the X3 2.5i, the manual front seats include a height adjustment; the X3 3.0i has 8-way power front seats and a memory system for the driver's seat and exterior mirrors. The steering wheel is tilt/telescopic adjustable. Storage space is generous: Each front door has two storage bins, the forward one with a flexible net; each rear door has a single bin. For the front occupants, the center console includes a storage compartment and (in the standard-equipped 2.5i) two cupholders; in the 3.0i and Premium Package-equipped 2.5i, a center armrest and single cupholder replace the two-cupholder configuration and an additional retractable cupholder is positioned in the dash for the front passenger. In either configuration, the console compartment accommodates an available 6-disc CD changer accessory.
The rear-seat backrest is split 60/40, the two portions folding down to provide cargo- and people-carrying versatility. In the "60" portion, a folding center armrest includes two cupholders, a storage compartment and the center head restraint.
Safety and security: continuing evolution, plus a new Head Protection System
All contemporary BMWs provide excellent occupant protection; for the X3 Series, BMW's Research and Innovation Center (FIZ) in Munich, Germany has carefully evolved the company's established safety concept. Both front-impact airbags, for example, have been further developed to optimize their 2-stage, accident-severity-dependent deployment characteristics, their inflated shape, and their interaction with surrounding surfaces and components. Front safety belts include automatic tensioners and force limiters. And the standard-equipment Head Protection System for front and rear occupants is newly 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, they signal for deployment very early in a side impact, yet still minimize the chance of an unwanted development.
Interlocking door anchoring system. This familiar BMW feature employs aluminum reinforcing bars in each door to strengthen the body side. At the aft end of each diagonally positioned aluminum bar is a hook-like member that, in the event of 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 ultra-sophisticated electronic control scheme itself, fiber-optic cables are employed since they 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
BMW anticipates that X3 buyers will be particularly eager to personalize their vehicles to suit their varied lifestyles. To this end, a wide and appealing range of options, both Packages and stand-alone, is available.
2.5i Premium Package. One of the most extensive ever offered by BMW, this Package includes front foglights, rain-sensing windshield wipers, automatic climate control, a 4-function On-board Computer, a leather-wrapped steering wheel with BMW's convenient multi-function controls, including cruise control; an auto-dimming interior rearview mirror; power front seats with driver's-seat/exterior-mirror memory; Maple Sycamore Dark interior trim; front center armrest; storage net in front passenger's footwell; upgraded interior lighting; attachment rails and a reversible, slip-proof mat for the cargo area; and BMW Assist, described later. Also part of this Package, a new Panorama Moonroof consists of two glass panels, both of which can be tilted up at the rear. The forward, larger panel can also be slid open; together, their glass area is nearly 10 square feet. Although the glass is effectively tinted, there is also a power-operated interior shade.
3.0i Premium Package. Includes leather upholstery, 4-way power lumbar support for the front seats, auto-dimming mirror, wood interior trim, Panorama Moonroof and BMW Assist. All other features of the 2.5i Premium Package are standard in the 3.0i model.
Sport Package. Essentially the same for both models except for wheel design; includes sport suspension, 18 x 8.0 wheels, 235/50R-18 H-rated all-season tires, Shadowline (black) exterior trim, sport front seats and a sport steering wheel.
Cold Weather Package, identical for both models; high-intensity liquid headlight cleaning system, heated front seats and an interior ski bag.
Light Package. Only for the 2.5i, this group includes Xenon Adaptive headlights, front foglights, automatic headlight control and rain-sensing windshield wipers.
STEPTRONIC automatic transmission. Optional on both models; 5-speed with Sport and Manual shift modes.
Servotronic power steering. Vehicle-speed-sensitive power assist in place of the standard engine-speed-sensitive system.
18-in. wheels and performance tires in differentiated front/rear sizes; available only on the 3.0i in combination with that model's Sport Package.
Cruise control and leather-wrapped steering wheel with multi-function controls. Optional on 2.5i, standard on 3.0i.
Xenon Adaptive headlights with auto-leveling. In addition to the forward illumination benefits of Xenon low- and high-beam lamps, Adaptive Light Control (ALC) literally "aims" at making night driving safer. With the headlight switch in its Automatic position, as soon as the vehicle is moving forward, the outboard lights steer with the front wheels, guided by an electronic control system and swiveled by small servo motors. The system responds not simplistically to the steering angle, but also to vehicle speed and the "yaw rate," or the rate at which the vehicle's direction is changing. The driver benefits from enhanced night vision around corners and curves. If the vehicle is stationary or backing up, the feature is inactive. Auto-leveling of the headlights is also included.
Front foglights. Though included in two option Packages, foglights are also available as a stand-alone option on the 2.5i. They're standard on the 3.0i.
Park Distance Control - Via ultrasonic sensors in the front and rear bumpers, PDC senses when the vehicle is approaching obstructions that may not be visible to the driver. Beepers at the front and rear of the cabin alert the driver.
Power-fold mirrors, for parking in tight spaces or navigating certain car washes. At the touch of an additional button on the power-window control panel on the driver's door, the exterior mirrors fold inward.
Metallic paint, available in seven colors including Flamenco Red, Black Sapphire and Titanium Silver.
Panorama Moonroof - part of both models' Premium Package, but also available as a stand-alone option.
BMW On-board Navigation System, available in both models. Includes an 8-function On-board Computer.
4-function On-board Computer - optional in 2.5i, standard in 3.0i.
Leather upholstery - includes seats and door armrests; part of the 3.0i Premium Package, but available as stand-alone option for both models.
Wood or aluminum interior trim. The Premium Package for both models includes Maple Sycamore Dark wood trim. For X3s equipped with this Package, the customer may specify either Birch Grain Light wood or a very contemporary aluminum-finish material with an attractive repeated-oval pattern.
Power front seats - though part of the 2.5i Premium Package, available also as a stand-alone option; include driver's-seat/exterior-mirror memory.
Heated front seats - available singly for customers who do not wish to order the Cold Weather Package.
Heated steering wheel - available in both models; in the 2.5i it requires the Premium Package. Not available in combination with Sport Package.
Premium audio system with DSP - optional both models. The speaker count (10, including two subwoofers) is the same as that for the standard system, but speakers and other elements are upgraded.
SIRIUS 100-Channel Satellite Radio System center-installed accessory (requires optional Sirius Satellite radio prep.)
6-disc CD changer, available for BMW SAV Center installation in the center console.
Auxiliary Audio Input, allows audio inputs from cassette, MP3, and other audio devices to be played through the sound system.
Privacy glass aft of the B-pillar.
Rear-seat side-impact airbags, available in both models; the front and rear Head Protection System is standard.
Cargo net. Retractably carried in a roller assembly, the net can be attached to the rear-seat backrests with them folded or upright, giving two choices of partitioning between cargo (or pets) and occupants.
Other BMW SAV Center-installed accessories. In addition to the CD changer, a variety of other accessories will be available for installation by BMW SAV Centers. Though not all items will be available at launch, the selection will eventually include aerodynamic exterior components, carrier systems that attach to the standard roof rails, chrome exhaust extensions, wood shift knobs and handbrake grips, and wood or aluminum interior trim that can be retrofitted to X3s not already so equipped.
BMW Assist: important new option
In the recent past, BMW Assist - a comprehensive program of safety- and convenience-oriented customer services - has been a part of the available BMW On-board Navigation System and center installed telephone. Now these services, in enhanced form, are offered as a stand-alone option as well as being included in both X3 Premium Packages. The in-vehicle equipment for BMW Assist includes GPS technology and an "SOS" and "Wrench" button console that in the X3 Series is in a panel above the windshield. Vehicle occupants may request emergency or other services simply by pressing the button; the BMW Assist system transmits the location and vehicle information to the BMW Assist Response Center. A response specialist then speaks with the occupants to coordinate dispatch, notify emergency contacts on file, and link BMW Roadside Assistance or emergency services as needed and requested. Deployment of an airbag automatically activates BMW Assist as well. A year's subscription to BMW Assist is included with the option; after the initial year, the annual fee is $240. In addition to the safety-related benefits, subscribers can call a toll-free 800 number to avail themselves of many BMW Assist Concierge services, from travel planning to dining reservations, shopping assistance and event tickets.
Like all current models, each X3 is covered by BMW's 4-year/50,000-mile limited warranty and comes with a 4-year/50,000-mile Full Maintenance Program for customer convenience, peace of mind and economic benefit.
"Der Allrad-Sportler" Auto Zeitung, the German magazine, titled its driving impression of the X3 Der Allrad-Sportler - which translates to "The All-Wheel-Drive Athlete" - and characterized the new BMW SAV this way: "It looks like a contemporary SUV and resembles the X5. And yet the true domain of the new X3 is curving terrain. After our first impressions offroad, on sandy roads, country roads and stretches of Autobahn, the X3 earns the title of 'sports wagon with offroad capabilities." We couldn't have said it any better than that; it would seem that BMW has achieved the goals it set for the X3.
Performance with a conscience
BMW strives to produce its motor vehicles and other products with the utmost attention to environmental compatibility and protection. Integrated into the design and development of BMW automobiles are such criteria as resource efficiency and emission control in production; environmentally responsible selection of materials; recyclability during production and within the vehicle; elimination of CFCs and hazardous materials in production; and continuing research into environmentally friendly automotive power sources. Tangible results of these efforts include the recycling of bumper cladding into other vehicle components; water-based paint color coats and powder clear coats; near-future availability of hydrogen-powered models; and various design and engineering elements that help make BMWs easier to dismantle at the end of their service life.
BMW Group In America
BMW of North America has been present in the United States since 1975. Since then, the BMW Group in the United States has grown to include marketing, sales and financial service organizations for the BMW and MINI brands and Rolls-Royce Motor Cars; DesignworksUSA, an industrial design firm in California; a technology office in Silicon Valley and various other operations throughout the country. BMW Manufacturing Corp. in South Carolina is part of BMW Group's global manufacturing network and is the exclusive manufacturing plant for all Z4 roadster and X5 Sports Activity Vehicles. The BMW Group sales organization is represented in the U.S. through networks of 340 BMW car, 327 BMW Sports Activity Vehicle, 148 BMW Motorcycle retailers, and 73 MINI dealers. BMW (US) Holding Corp., the BMW Group's sales headquarters for North, Central and South America, is located in Woodcliff Lake, New Jersey.
BMW of North
Base Price USA Port of Entry
X3 2.5i $30,995
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