We're not sure why BMW is reticent to put forth a new Motorsports model of its Z4 folding hardtop convertible, but it has effectively introduced such a model in all but name here at the Detroit Auto Show. Inscrutably dubbed Z4 sDrive35is (we're guessing you can hit extralegal speeds by the time you successfully spit out its name), the new model features a revised twin-turbo 3.0-liter inline-six that spits out 340 horsepower and 332 pound-feet of torque, with an overboost function capable of a momentary bump up to 369 torques. Paired with BMW's seven-speed Sport Automatic dual-clutch transmission, the drivetrain is good for 0-62 miles-per-hour in in 4.8 seconds.
Additional alterations include a ride height that's lowered by 10 millimeters thanks to the adaptive M suspension, a revamped front fascia with matte aluminum trim bars, Oxide Silver mirror caps, and 19-inch alloys among other niceties – you can check out the complete roster of changes by checking out the press release after the jump.
M badges or no, we want one.
The Top Performer in the Roadster Range: The BMW Z4 sDrive35is.
Munich. Combining classic proportions with modern sportiness, the new BMW Z4 has reached the top of its market segment almost overnight. And now this charismatic roadster is entering a new dimension in driving dynamics, the new BMW Z4 sDrive35is offering an even higher standard of performance ensured both by the modified straight-six power unit with BMW Twin Turbo Technology and High Precision Injection, on the one hand, and by BMW's seven-speed Sport Automatic with double clutch operation and the M Sports Package including the adaptive M Suspension likewise featured as standard, on the other. Appropriate optimisation in engine technology increases maximum output of the 3.0-litre power unit to 250 kW/340 hp. Peak torque is 450 Newton-metres/332 lb-ft, increasing briefly with the Overboost function to 500 Newton-metres/369 lb-ft. The outstanding power and performance of the BMW Z4 sDrive35is is expressed in particular by the significant increase in pulling power and muscle to be clearly experienced in all situations. In conjunction with seven-speed Sport Automatic featuring double clutch operation, this new top-of-the-range
Roadster accelerates from a standstill to 100 km/h (62 mph) in just 4.8 seconds.
At 9.0 litres/100 kilometres (equal to 26.1 mpg US) and 210 grams in the EU test cycle, fuel consumption and CO2 emissions are the same as on the BMW Z4 sDrive35i with Sport Automatic.
The BMW Z4 sDrive35is is making its world debut at the 2010 North American International Auto Show (NAIAS) in Detroit. And parallel to the market launch of this high-performance roadster in spring 2010, the M Sports Package is being introduced for all further versions of the BMW Z4.
More air, more boost, more torque, more driving pleasure.
The twin-turbo straight-six power unit already giving the BMW Z4 sDrive35i truly impressive dynamics and all-round performance is characterised in particular by its spontaneous and direct response to the gas pedal, fascinating free-revving performance, and unusually economical use of fuel for a car in this class.
Now the outstanding potential of this power unit is being put to even greater use in the new version of the BMW Roadster, features such as optimised air supply and increased boost pressure ensuring an even better flow of power with the same high standard of efficiency.
The combination of BMW Twin Turbo Technology and High Precision Injection offers a level of performance a naturally-aspirated power unit would only be able to provide with a larger number of cylinders and extra displacement, meaning far higher weight and significantly greater fuel consumption.
Instead, the BMW Twin Turbo power unit uses two small turbochargers which, through their low inertia, cut in from the start at relatively low engine speeds, each supplying three cylinders with compressed air. As a result, power and performance are built up with a level of spontaneity quite unusual on a turbocharged engine. The turbocharger system developed for the power unit of the new BMW Z4 sDrive35is maintains a high boost pressure throughout the entire load range. Peak torque now increased to 450 Newton-metres or 332 lb-ft comes from a low 1,400 rpm and is maintained consistently all the way to 4,500 rpm. Maximum output of 250 kW/340 hp, in turn, is delivered at 5,800 rpm.
Overboost function for particularly dynamic acceleration.
Modified engine management on the BMW Z4 sDrive35is also allows the use of an Overboost function briefly increasing engine torque under full load by another 50 Newton-metres or 37 lb-ft. The peak thus offered of 500 Newton-metres/369 lb-ft gives the car particularly fast, dynamic and powerful acceleration, the BMW Z4 sDrive35is completing the sprint from a standstill to 100 km/h (62 mph) in just 4.8 seconds.
Through its particular characteristics, the power unit offers a particularly intense experience of this supreme performance. The extra output of the optimized
six-cylinder is maintained consistently throughout all load ranges, above all under very dynamic driving conditions.
When accelerating in the BMW Z4 sDrive35is, the driver feels the additional torque and muscle particularly at medium and high engine speeds. Following the policy of the BMW Group, finally, top speed of the BMW Z4 sDrive35is is limited electronically to 250 km/h or 155 mph.
High Precision Injection: the efficient way to supreme performance.
The BMW Z4 sDrive35is offers its outstanding power and performance consistently at all times. But this does not mean an increase in fuel consumption and emissions. On the contrary – averaging fuel consumption of 9.0 litres/100 kilometres (equal to 26.1 mpg US) and CO2 emissions of 210 grams per kilometre in the EU test cycle, the new top model offers the same superiority also in this respect as the BMW Z4 sDrive35i with Sport Automatic.
This unusually good balance of performance and fuel consumption results from the fundamental design and layout of the six-cylinder combining BMW Twin Turbo Technology with High Precision Injection. So once again, the qualities of direct gasoline injection featured in this engine come out very clearly, piezo-injectors positioned in the cylinder head between the valves and therefore in the immediate vicinity of the spark plugs ensuring particularly precise dosage of fuel and a clean combustion process.
Opening up to the outside, the injectors operate at a pressure of up to 200 bar, distributing fuel in a conical spray pattern throughout the entire combustion chamber. A further advantage of such direct fuel injection is the cooling effect allowing higher compression and making the combustion process even more efficient.
Through their concept alone, the turbochargers likewise help to reduce fuel consumption. Since the turbines are made of special steel particularly resistant to high temperatures and therefore able to cope with temperatures of more than 1,000° C or 1,830° F, there is no need for an increased fuel supply with its cooling effect. Particularly under full load, this ensures a significant advantagein fuel economy.
Further technologies offered as standard by BMW EfficientDynamics such as Brake Energy Regeneration, EPS Electric Power Steering and on-demand control and management of ancillary units likewise help to reduce both fuel consumption and emissions.
Characteristic engine sound accompanying the dynamic surge of power.
The modified six-cylinder also comes with special features on the engine block itself in the interest of even greater strength and stiffness. The exhaust system of the BMW Z4 sDrive35is, in turn, has been developed specifically for this model, appropriate sound engineering giving the car a very characteristic and truly impressive sound pattern.
This particular distinction tailored to the BMW Z4 sDrive35is is ensured by special sound flaps and modifications on the silencers. The driver and passenger therefore experience powerful acoustic feedback to their wish for performance, without the sound of the engine becoming obtrusive, let alone annoying, at any time. So the sound experience is characterised by a particularly deep rumble with the focus above all on the low frequency range.
Seven-speed Sport Automatic with a special control map and an optimised two-mass flywheel.
The seven-speed Sport Automatic with double clutch operation featured in the BMW Z4 sDrive35is likewise offers the very best in driving dynamics and efficiency. A particular highlight in this case is the two-mass flywheel laid out particularly for an even higher level of power and performance, offering even greater strength and stability and naturally handling high engine torque of up to 500 Newton-metres or 369 lb-ft without the slightest problem.
The seven-speed Sport Automatic with double clutch operation shifts gears without the slightest interruption of torque and engine power, offering the driver the choice of an automatic gearshift or the manual selection of gears. The fast and particularly smooth change of gears ensures unusually harmonious acceleration and serves in addition to reduce both fuel consumption and emissions.
The control map on the seven-speed Sport Automatic transmission with double clutch has naturally been tailored to the particular power and performance of the engine, thus further enhancing the superior sportiness of the BMW Z4 sDrive35is to an even higher level. Particularly when shifting gears manually and in conjunction with the SPORT and SPORT+ modes of Dynamic Driving Control, the transmission offers a most dynamic experience through modified gearshift points, optimised selection of gears and an even greater increase in torque before shifting.
Sport Automatic also comes with a Launch Control function for maximum performance when accelerating from a standstill.
The Sport Automatic transmission is controlled and masterminded by an electronic gear selector on the centre console and comes with gearshift paddles on the steering wheel.
Featured as standard on the BMW Z4 sDrive35is: M Sports Package and adaptive M Suspension.
The BMW Z4 sDrive35is also comes as standard with an M Sports Package including the M Aerodynamics Package and adaptive M Suspension featuring electronically controlled dampers for even greater agility without making any concessions in terms of comfort. The M Sports Package underlines the dynamic character of the car through its aerodynamically optimised exterior features and customised interior design. Special 18-inch light-alloy rims in five-spoke design combined with tyres of different size front and rear round off the sporting character of the BMW Z4 sDrive35is, with 19-inch light-alloy rims available an option.
The adaptive M Suspension lowers the entire car by 10 millimetres or almost 0.4", ensuring a quick reaction to sudden steering manoeuvres and superior precision when entering a bend thanks to four continuously adjustable twin-sleeve gas-pressure dampers with interacting adjustment of the inbound and rebound strokes. The central control unit processing data delivered by three accelerometers and adjusting the four dampers independently of one another enables the suspension to respond very quickly to even the slightest change in driving and road conditions. Damper harshness, in turn, is adjusted by externally fitted valves controlling the flow of damper fluid, giving the dampers either a harder or softer set-up in accordance with current conditions and driving requirements. Reaction time of the system is extremely short, with the rear dampers being adjusted immediately as soon as the front wheels run over a hole or bump in the road.
Electric Power Steering on the BMW Z4 sDrive35is features a particularly sporting and dynamic control map, with the focus on intense and clear feedback to the driver through the dosage of power assistance provided by the electric motor. Again, this enables the driver to enter bends with extreme precision at all engine speeds in the interest of enhanced performance.
M Sports Package offering a most direct experience of the car's dynamic potential – and available as an option also on the other models in the range.
The exterior and interior features of the M Sports Package coming as standard on the BMW Z4 sDrive35is raises the dynamic driving potential of the car to an even higher level and clearly presents the particular qualities of this model through its looks alone.
Upon introduction of the new top model in the range, the M Sports Package is also becoming available as an option on the other versions of BMW's unique Roadster. The only difference is that instead of the wheels exclusive to the BMW Z4 sDrive35is, the other models come with 18-inch M light-alloy wheels on the
M Sports Package.
The particular exterior features on the BMW Z4 sDrive35is include a striking front bumper with a horizontal trim bar in the outer air intakes finished in matt aluminium, like the bars in the BMW kidney grille. The slightly twisted contours of these trim bars take up the spoke design of the light-alloy rims as a further sign of distinction.
The rear bumper comes with specially accentuated surrounds on the exhaust tailpipes as well as a two-piece diffuser again created specifically for the BMW Z4 sDrive35is, finished at the top in body colour and featuring a black grained surface at the bottom. The M Aerodynamics Package included in the optional M Sports Package also on the other versions of the Z4 Roadster furthermore comes with a rear bumper insert in Anthracite metallic.
Inside the BMW Z4 sDrive35is, the driving experience is enhanced to an even higher standard by features such as the M leather steering wheel with its gearshift paddles, an M footrest and sports seats. The instrument cluster comes with grey faces on the dials and the "sDrive35is" model designation in the instrument cluster.
Further features inside the BMW Z4 sDrive35is are the Anthracite-coloured BMW Individual roof lining, M entry strips, footmats with coloured piping and the "sDrive35is" model designation, as well as M interior trim in Aluminium carbon.
The M Sports Package on the other versions of the Z4 Roadster includes an M gearshift lever knob in leather on the manual gearbox models. At the same time the range of leather upholstery is being further enhanced by an additional colour variant marking the launch of the BMW Z4 sDrive35is: Both the top model and all other versions of the Z4 Roadster are now also available in Kansas Walnut leather as yet a further option.
The BMW Z4 sDrive35is comes with a choice of six paintwork colours. In addition to Alpine White and the metallic colours Titanium Silver, Sapphire Black, Space Grey and Deep Sea Blue, the Z4 Roadster is now available for the first time in Melbourne Red metallic.
Regardless of the colour chosen, the exterior mirror caps on the BMW Z4 sDrive35is always come in Oxide Silver. Another optical feature on the top model, finally, is the "sDrive35is" model designation on the front side panels.