Road Trip: 2007 BMW 3-Series Convertible - EXCLUSIVE VIDEO INTERVIEW
Take a Road Trip with The Auto Channel in the all new 2007 BMW 3 Series hardtop convertible.
EDITOR'S NOTE: This page contains an embeded two-part video. In part 1 Michael Brachvogel, BMW's Deputy Product Manager for the 3 Series, describes the design and functionality of the first-for-BMW retractable hardtop. In part 2 The Auto Channel's Marc Rauch rides along on the road from Key Largo to Miami as Michael talks about how BMW approached designing the 3 Series Convertible and Coupe, and about the vehicles' superb driving characteristics and capabilities. To ride along just click the PLAY buttons on the embeded video windows.
See also: BMW Buyers Guide.
Few other automobiles stir emotions quite like a convertible. Whether it's the feeling of freedom created by top-down driving or their seductive shapes, convertibles have long been regarded by many car enthusiasts and casual onlookers alike as providing a one-of-a-kind exhilarating driving experience.
As proof of their special lure, late last year Neiman-Marcus sold 50 specially equipped BMW M6 Convertibles featured in the retailer's Christmas catalog in one minute, 32 seconds.
The roof opens automatically in a flowing motion as each of the three elements rests above the other to create a compact package.
The roof and luggage compartments are separated from one another by a partition that swivels when the roof is closed to provide maximum luggage capacity. Another convenient feature is that the roof can open by remote control when the car is equipped with the Comfort Access option . Like the roof controls within the interior, the remote control button must be kept pressed down for safety during the entire opening process because movement of the roof elements is interrupted whenever the button is released.
A fresh interpretation of a traditional shape
The shape of the new BMW 3 Series Convertible is characterized by well-balanced proportions that create an unmistakable silhouette. The long hood reflects BMW's adherence to the tradition of inline 6-cylinder engines. The long wheelbase, short overhangs, set-back passenger compartment and low roof line are all traditional BMW 3 Series Convertible characteristics.
The front view reveals a significant distinction from the current 3 Series Sedan and Sports Wagon. The contours of the hood as well as the design of the front air dam and headlights give the new BMW 3 Series Convertibles a particularly low and sporty look. The hood's powerdome alludes to the unique driving experience that awaits. Its lines form a powerful silhouette extending all the way from the A-pillars to the outside corners of the BMW kidney grille.
Since there are no conventional B-pillars, the feeling of open-air driving can still be achieved with just the side windows opened. Approaching the C-pillars, the traditional "Hofmeister kink" can be clearly seen. The rear window is fixed glass with an electric defroster for safety and convenience. The rear and side windows are 30 percent larger than their predecessors, offering improved rear visibility.
The headlight units on the new BMW 3 Series Convertibles have a unique look. With the hood extending beyond the headlights, they appear to have been sliced-off at the top creating a sense of powerful, concentrated focus. The convertibles come standard in the U.S. with Xenon Adaptive headlights, highlighted by BMW's corona light rings. The rings can not only serve as daytime running lights (if that feature is selected via the Vehicle & Key Memory System), but also draw attention to BMW's characteristic four round headlights, making the new convertible instantly recognizable as a BMW, day or night.
The taillights are integrated flush into the body, and the lights are split into two sections and extend up the trunk lid, blending with the character line from the side profile. Horizontal LED taillights give the car an unmistakable look at night. The horizontal flowing lines accentuate the convertible's wide track and low stance.
The 3 Series Convertibles' navigation and radio antennae are integrated within the car in order to not detract from the clean lines of the bodywork. Radio reception with the roof open is ensured by aerials in the side panels, while aerials in the rear window are automatically activated as soon as the roof is closed. Convertibles with the optional SIRIUS satellite radio are equipped with a separate antenna mounted on the rear deck lid.
Flowing lines provide an elegant interior
The controls for air conditioning,
The side panels feature a smooth and sweeping design flow that extends from the dashboard to the backrests of the two rear seats. The center console also extends to the rear, serving as a storage compartment between the rear seats. Ambiance lighting, mounted on the door and the rear side panels, projects a warm, indirect lighting effect.
New engines provide more power & save weight
Progress immediately obvious by pressing the accelerator
The 328i Convertible's N52 3.0 liter, 230 hp inline 6-cylinder engine features magnesium/aluminum construction and BMW's innovative Valvetronic system which eliminates the conventional throttle body for throttle control, technology found only on BMW engines. Compared to the M54 engine family of the new 3 Series Convertibles' predecessors, the N52 achieves impressive progress on all fronts.
The new engine has more power: 230 hp vs. 184 hp, greater torque: 200 lb-ft. vs. 175, and torque characteristics across the broad range of engine speeds. Its "red line" is 7,000 rpm compared to 6,500 for the M54. Model for model, EPA mileage ratings are either the same or improved – this, with dramatically improved performance.
The N52 weighs 22 lb. less than its predecessor. Had BMW engineers developed the previous engine to meet their goals, it would have added approximately 30 lb. and thus would have weighed 52 lb. more than the new engine. Because there is just one external drive belt, compared to the previous two, overall engine length is about an inch shorter.
An aluminum/magnesium engine block exclusive to BMW, hollow camshafts, plastic camshaft cover, improved combustion chambers, a further evolved Double VANOS , higher fuel injection pressure, all-new engine electronics, an electric coolant pump, a variable-volume oil pump and an oil/coolant heat exchanger are the other weight-saving features and improvements of the new engine that can be noticed with application of the accelerator pedal. Speaking of which, acceleration from 0 to 60 mph is achieved in a spirited 6.7 seconds for the 6-speed manual and in 7.2 seconds for convertibles equipped with the STEPTRONIC 6-speed automatic transmission. The top speed of the 328i is electronically limited to 130 mph or 150 mph if equipped with the optional Sport Package.
BMW's other approach to modern 6-cylinder power
It is the most powerful engine within BMW's wide range of inline 6-cylinder driving machines that does not wear an "M" badge. This brand-new engine, designated N54, develops a maximum output of 300 hp in U.S. specifications from 3.0 liters displacement and generates peak torque of 300 lb-ft for powerful acceleration in any situation. And it achieves these results using technology that might surprise students of BMW history: turbocharging.
Although it is standard equipment on its highly acclaimed diesel engines, BMW has not used turbocharging with a road-going gasoline powerplant since the 1980's. Until now, the BMW 745i Sedan, which debuted in 1981, and the iconic BMW 2002 Turbo, introduced at the 1973 Frankfurt auto show, were the only two standard production, gasoline-powered BMWs to employ the technology.
While the technology works as advertised, BMW engineers were not satisfied with the most often-cited downside to turbocharging; the frustrating lag between when the driver presses the accelerator pedal and when the turbocharger develops sufficient rotation to increase power. Typical turbo lag is at its worst at low engine speeds. Other drawbacks included relatively high fuel consumption; in addition, available materials did not always fare well under the high-heat, high-rpm operation of the turbocharger, which gets its energy from hot, flowing exhaust gases and typically spins up to 5-figure rpm's. For these and other reasons, BMW put turbocharged gasoline engines on the shelf for more than 20 years.
Two recent developments caused BMW to reconsider turbocharging: a trend among many luxury-performance carmakers to achieve power gains by building engines of ever-increasing displacement and technology transfer from turbocharged diesel engine development to their gasoline-fired counterparts.
Accordingly, BMW recently articulated its new approach to developing high-performance engines as part of its EfficientDynamics initiative. Beginning with the N52 normally aspirated engine and the N54 turbocharged unit, BMW will achieve its performance goals with smaller, lighter, more efficient and cleaner-running engines.
The all-new N54 features twin, relatively small turbochargers to boost performance significantly, but, at the same time, minimize the response lag. Thanks to their lower inertia, two small turbochargers build up pressure much faster than a single, large turbocharger, thus eliminating even the slightest response lag. The front turbocharger feeds cylinders 1-3; the rear unit delivers super-compressed air to cylinders 4-6.
A further advantage of turbocharging is that this is the most weight-efficient method to boost engine power and performance. The N54 turbocharged inline 6 weighs approximately 150 lbs. less than an equally powerful eight-cylinder engine displacing 4.0 liters. This lower weight means a significant advantage not only in fuel economy, but also in balancing the car's weight distribution.
To enhance efficiency, the turbochargers are made of a particularly heat-resistant material which makes them immune to high exhaust gas temperatures in the interest of a fuel-efficient combustion process particularly under full load.
As a result, the twin turbo technology in the BMW 335i Convertible represents a significant achievement in terms of both performance and fuel economy. The advantages over a conventional turbocharged engine are not only clearly measurable, but easy to feel on the road.
This new high-performance engine gives the aerodynamically sculpted convertible outstanding acceleration and flexibility. The twin turbo powerplant develops its power and performance much more spontaneously than a turbocharged engine of conventional design.
At the same time the new engine offers all the smoothness and refinement which made BMW's award-winning inline sixes so admired. Last but certainly not least, the impressive increase in power on the twin turbo engine versus a conventional normally aspirated 6-cylinder engine comes without any increase in fuel consumption.
Turbocharging typically includes intercooling of the engine's induction air, in other words, cooling the compressed air that emerges super-heated by the compression process from the turbocharger(s). Sometimes it's done with coolant; in the case of the N54 engine, it's accomplished with outside air. Intercooling is desirable, often necessary, to reduce the temperature of the incoming air to preclude detonation or "knocking" that can reduce power or, in the extreme, damage the engine. Naturally, the N54, like the N52 and all other current BMW engines, is equipped with knock control.
As effective as the magnesium/aluminum engine construction is for saving weight, the significantly increased loads and cylinder pressures of the N54 300-hp engine required the use of an aluminum engine structure with cast-iron cylinder sleeves. Of course, some, but not all, of the N52's magnesium/aluminum weight saving was lost. The N54 weighs 419 lb., the N52, 357 lb.
A new high-precision direct fuel injection system with Piezo injectors also enhances performance and fuel efficiency. A second-generation evolution of the system found on the 760's V12 engine, it is a key factor in achieving BMW's goals for this engine. The new system's main advance over its predecessor is that it provides the engineers a greater degree of freedom in the calibration of fuel quantity and timing and the distribution of the fuel-air mixture in the combustion chamber.
A Piezo injector, a recent advancement in fuel injector technology, uses an actuator that takes the place of the solenoid valve in a conventional injector. The actuator, which works much faster than the solenoid, significantly reduces the injector's response time. That results in, according to researchers who led the Piezo injector's development, a 2-3 percent fuel savings and 20 percent less emissions.
The 335i Convertible's dual exhaust system runs at both sides of the vehicle - logical, as each contains its own turbocharger turbine and therefore requires extra space. At low loads, a flap channels most gas through one side to reduce low-frequency exhaust "rumble." The 335i features an air-to-air external oil cooler mounted in one wheel well as opposed to the N52's coolant-to-oil unit.
The peak power of 300 hp has already been mentioned; this is 45 more than last year's 330Ci and 70 up on the new 328i Convertible. At least as important is the fact that this engine can deliver its peak torque from 1400 rpm - not far above idling - to 5000 rpm. On the road, this power and torque result in outstanding performance. The 335i Convertible equipped with the 6-speed manual transmission accelerates from 0-60 mph in just 5.5 seconds; 5.7 seconds with the 6-speed STEPTRONIC automatic transmission. This sense of urgency continues all the way to the electronically limited top speed of 150 mph when equipped with the optional Sport Package.
New automatic transmission with optional shift paddles
A thoroughly enhanced 6-speed STEPTRONIC automatic transmission is available as an option on both models to meet the greatest demands for comfort and performance. A quicker and more responsive hydraulic control system, together with an innovative new torque converter and significantly enhanced control software ensure reaction times that are 40 percent faster than conventional automatic transmissions. In addition, gear change time has been almost halved. The torque converter clutch connects the engine more directly to enhance performance, quicken response and improve fuel economy.
If the driver wishes to control the transmission directly, paddles on the steering wheel provide direct gear selection when in manual mode. Because the gear shift paddles can be activated directly at any time, even if the selector lever is in Drive, the manual gearshift function always provides extremely spontaneous performance. Shift paddles are an available option on the 335i when ordered with automatic transmission and Sport Package.
Innovative suspension technology for maximum precision
Featuring a double-pivot McPherson strut-type aluminum suspension in front and a 5-link independent rear suspension, the new BMW 3 Series Convertibles boast the most advanced suspension in their class. Further advantages are a low center of gravity, well-balanced axle load and special damper set-up to give the new convertibles their impressive dynamic driving qualities.
The standard 17-inch alloy wheels run on 225/45R17 tires with run-flat technology. Even with a complete loss of air pressure in one tire, the vehicle can continue to be driven for up to 150 miles at 50 mph to get to the nearest service station. BMW's new Tire Pressure Monitor warns the driver as soon as the pressure in any tire drops more than 25 percent below the optimum level.
Dynamic Stability Control: enhanced functions for peace of mind and
The 3 Series Convertibles' highly effective Dynamic Stability Control (DSC) has been upgraded with new functions. The latest generation of DSC technology controls brake functions and vehicle stability on slippery roads by applying individual wheel brakes and reducing engine output. Enhanced functions of this system include:
- • Brake Drying. By lightly applying the pads periodically in wet
weather conditions to dry them, optimum stopping power can also be
experienced in the wet.
• Brake Standby. Preloads the brake pads to enhance brake response whenever the driver suddenly lifts off the accelerator pedal.
• Brake Fade Compensation. Maximizes brake pressure in extreme driving conditions for consistent brake pedal pressure no matter how hot the brakes become.
• Cornering Brake Control. Counteracts unwanted oversteer when applying the brakes slightly in a bend and, in conjunction with Active Steering, can countersteer appropriately to maintain stability.
• Start-off Assistant. Holds the vehicle for three seconds when stopped going uphill to prevent rolling back when releasing the brake pedal.
• Dynamic Stability Control ensures optimum traction on loose surfaces, while Dynamic Traction Control can be adjusted to raise the threshold when it intervenes for a sportier style of driving, allowing light wheel slip on the drive wheels. DSC may be deactivated completely if the driver desires.
The convertible bodyshell: light and torsionally stiff
The intelligent combination of innovative and proven materials, as well as modern production technology, gives the new BMW 3 Series Convertibles a particularly light but at the same time very stable body - BMW's body development specialists have achieved the highest level of torsional stiffness ever in a BMW Convertible.
Unladen weight of the convertible is approximately 400 lbs. more than that of the BMW 3 Series Coupe. This extra weight results from the installation of additional support members in the floor and the electric motors and hydraulic elements required for the retractable hardtop.
New plastic inside front fenders weigh 50 percent less than conventional steel panels. And unlike conventional plastic, the new panels are made of a synthetic material and no longer have to be painted separately. Instead, they go through the regular painting process together with the complete body-in-white.
Deformation areas at the front of the car, together with other features, serve to help provide optimum occupant protection in a frontal collision. The bulkhead support is made of high-strength steel with longitudinal profile bars and reinforcements. In addition, the extra-strong luggage compartment floor and rear and side panels help minimize the consequences of a collision from behind.
In a side impact, forces acting on the car are diverted to the opposite side through the reinforced floor pan. The side sills are made of steel that varies in geometry for greater resistance to bending. Interacting with the doors, the seats and the instrument panel, the specially made components ensure maximum stability between the A-pillars.
The carefully designed arrangement and dimensions of the convertible's load-bearing structures, crash boxes and deformation zones help to keep impact energy away from the driver and passengers. Restraint and support systems are tailored to one another and controlled by one unit to ensure proper protection for each occupant. The front and side airbags, belt latch tensioners and belt force limiters are activated by the car's sensor-controlled safety electronics based on the type and severity of the impact.
The side airbags are integrated into the seat backrests and inflate, in the event of a significant side-impact collision, over a large area extending from the bottom of the backrest all the way to the upper edge of the headrest to provide upper body and head protection regardless of seating position.
Extra safety in the event of a rollover is provided by the windshield frame that serves as a safety bar. Rollover sensors that constantly monitor all vertical and horizontal movements of the car can activate rollbars positioned behind the rear headrests. The belt latch tensioners on the front seats as well as the side airbags are activated within fractions of a second.
The interior: ample space, extra freedom
The new BMW 3 Series Convertibles offer open-air driving pleasure for four. The front seats come with integrated belt systems and the center console extends all the way to the rear, splitting the rear compartment into two single seats. Thanks to their low seating position, these models offer generous head room.
Rear shoulder room is increased by 3.15 in. and elbow room grows 4.72 in. over the previous model. Access to the two rear seats is facilitated by the seat release lever fitted at the top of the seat backrest and the 2-speed fore-aft power adjustment switch.
Measuring 9.0 cu ft. with the hardtop up, luggage capacity is very generous. And even with the roof down, the remaining capacity provides ample space for additional necessities. By folding the rear seat backrest down, bulky objects can be loaded on the flat area behind the rear seats, without the risk of harming the upholstery.
The optional pass-through between the rear seat area and the luggage compartment makes the new 3 Series Convertible ideal for the driver and passenger traveling long distances and for many transport requirements in everyday use. The option includes a ski transport bag that is easily and conveniently set up in seconds and can be removed just as easily.
iDrive with Programmable Memory Keys
New BMW 3 Series Convertibles with the optional Navigation system feature BMW's iDrive system to control the Navigation, Climate, Entertainment and Communications functions. The new monitor automatically adjusts to ambient light conditions and is positioned in a perfect ergonomic arrangement in the instrument panel.
New to the 3 Series Convertibles are six Programmable Memory Keys on the dashboard that serve to simplify iDrive operation and control. Two additional new keys allow quick access to AM or FM radio stations and control the music source. The remaining six keys can be programmed for favorite items such as navigation destinations, radio stations or even telephone numbers. The keys are touch-sensitive; each respective function is clearly presented in the iDrive display as soon as the driver places his or her finger on the button.
Unique and premium equipment
Offering a wide range of safety and comfort features, the new BMW 3 Series Convertibles make every trip an experience in driving pleasure. To supplement the range of standard equipment, the newest BMW convertible is available with a wide choice of high-tech audio, navigation, Bluetooth and telematic functions.
New automatic air-conditioning features, for example, enhance the convertible's comfort. Automatic programs for ventilating the car selected through iDrive are supplemented by another mode: in addition to the three stages - "Gentle", "Medium" and "Intense" - the driver can activate a "Convertible" mode whenever the roof is open. This reduces the influence of the interior temperature sensor on the ventilation and control. Instead, temperature control and lower intensity are controlled as a function of the ambient temperature and sun glare.
The Convertible mode is available only with the roof open. As soon as the hardtop folds back over the passenger compartment, the automatic air-conditioning will return to the program last chosen when the car was closed, the Convertible mode then being automatically reactivated when the driver opens the roof again.
Automatic Air Recirculation (AAR) optimizes air distribution to provide a consistent temperature throughout the cabin. The system is automatically deactivated at speeds higher than 50 mph.
New sun-reflective leather for cooler seating
BMW is the first carmaker in the world to use sun-reflective technology to mitigate temperatures on leather seating, armrest surfaces, headrests, and gear shifter. The process uses modified color pigments imbedded in the leather during the production process to reflect the infrared radiation of the sun in wavelengths of more than 720 nanometers.
This new leather treatment is able to reduce surface temperatures on dark interior colors by up to 20 Celsius degrees (36 Fahrenheit degrees), and also offers advantages on light-colored upholstery, where the heating effect of sunshine is less severe, reducing the surface temperature by as much as 15 Celsius degrees (27 Fahrenheit degrees). All other qualities of the leather remained unchanged. An accessory wind deflector developed especially for the new BMW 3 Series Convertibles reduces air swirl within the interior, even at high speeds. The new deflector is fastened firmly in the rear of the passenger compartment by supports in the side panels and can be easily swiveled into position.
The new BMW 3 Series Convertibles - maintaining tradition, setting new
BMW 3 Series Convertibles have been known for their unique top-down driving experiences for 20 years. The first convertible based on the 3 Series debuted in model year 1987 and was the first open four-seater in this segment. Unlike many other of the open four-seaters that came afterwards, the BMW had a soft top that lowered completely beneath a metal cover to maintain its classic lines.
The beautiful style continued in the1994 model year with the second-generation 3 Series Convertibles; its large wheel arches and A-pillars slanted at a lower angle gave it an even more sporting and dynamic appearance. It was the basis for the first M3 Convertible sold in the U.S. market.
The third-generation 3 Series Convertibles were introduced in model year 2000 and continued the tradition of dynamic appearance and performance with its muscular shape and powerful engines.
All BMW 3 Series Convertibles quickly became classics during their lifetime. The objective in developing each new model was to adopt the elementary qualities so typical of the BMW 3 Series with modern, trendsetting features. The new generation both honors the original character of these outstanding automobiles and sets new standards for future generations of 3 Series Convertibles.
BMW Ultimate Service: providing owners with incredible value and peace of mind For Model Year 2007, BMW announces BMW Ultimate ServiceTM, a suite of services that includes the BMW Maintenance Program (formerly called Full Maintenance), Roadside Assistance, the New Vehicle Limited Warranty and BMW AssistTM with TeleService.
BMW Ultimate Service includes: The BMW Maintenance Program is the only no-cost maintenance program in the industry that covers wear and tear items like brake pads and rotors for 4 years or 50,000 miles, whichever comes first. BMW owners pay nothing for all scheduled inspections, oil changes, brake pads, wiper blade inserts and other wear-and-tear items.
BMW Roadside Assistance is one of the industry's most comprehensive plans available. Not only is it no-charge for the first 4 years, but there is no mileage limit. BMW drivers enjoy the assurance of on-the-road help 24 hours a day, 7 days a week, anywhere in the United States, Canada and Puerto Rico. This includes everything from flat tire changes, emergency gasoline and lock-out assistance, to towing, alternative transportation and even trip-interruption benefits. This service also includes valuable trip routing advice.
BMW New Vehicle Limited Warranty: All 2007 BMW passenger vehicles are covered by BMW’s excellent Limited Warranty, which includes: • New-vehicle warranty – 4-year/50,000-mile coverage of the vehicle. • Rust-perforation warranty – 12-year/unlimited-mileage coverage.
BMW Assist provides the driver with services that enhance on-the-road security and convenience, for added peace of mind. The BMW AssistTM Safety Plan is standard on all 5, 6, and 7 Series models, including M5 and M6, and is included in the Premium Package or available as a stand-alone option on all other models. Starting with MY 2007 vehicles, BMW is the only manufacturer that will offer this service for 4 years at no additional cost. Most other manufacturers cover only the first year of service.
The in-vehicle equipment for BMW AssistTM includes GPS technology and hands-free communication functions accessed via buttons in the overhead or center console. Vehicle occupants may request emergency or other services simply by pressing a button; the BMW AssistTM system then transmits the location and vehicle information to the BMW AssistTM Response Center. A response specialist will then speak with the occupants to coordinate dispatch, notify emergency contacts on file, and link BMW Roadside Assistance or emergency services as needed and requested. A severe accident automatically activates the BMW AssistTM call as well. The BMW AssistTM Safety Plan also includes Remote Door Unlock and Stolen Vehicle Recovery services, which can save the owner time and money.
TeleService automatically notifies the BMW center when a vehicle will need service. This feature allows the Service Advisor to proactively set up a customer appointment and have the needed parts ready.
BMW Assist subscribers can also enroll in the BMW Assist Convenience Plan (available at an additional cost of $199 per year) to avail themselves of many BMW AssistTM Concierge services, from travel planning to dining reservations, shopping assistance and event tickets, as well as receive directions, and traffic and weather information. On many models produced September 2006 and later, a selected destination and its phone number can be sent directly to the on-board navigation system and Bluetooth®–linked mobile phone, after a push of the new Concierge button. The Convenience Plan also includes Critical Calling, a new service that connects the driver in case their mobile phone is not in the vehicle or its battery is discharged. After pushing the SOS button, a BMW AssistTM response specialist will link the driver to his requested party for up to five minutes and for up to four events per year.
As before, the BMW Assist system includes Bluetooth® hands-free phone connectivity with hands-free phonebook access and dialing by name or number via the steering wheel controls. Use of this feature requires a customer-provided compatible Bluetooth® mobile phone.