October 27. 2005 BMW will redefine the benchmark for two-seater soft-top sportscars when the much-anticipated Z4 M Roadster arrives early next year. The M version of the Z4 will use the 3.2-litre straight-six powerhouse previously seen in the E46 BMW M3 Coupé and Convertible. Voted the World’s Best Engine in its class five years in a row at the international “Engine Oscars”, the 252 kW and 365 Nm straight-six M3 engine rockets the two-seater Z4 M Roadster to 100 km/h in just 5.0 seconds, and on to an electronically limited top speed of 250 km/h. Due to bow in at the Detroit Motor Show next January 2006, the ultra-sports version of the BMW Z4 Roadster has been long-awaited by keen open-top drivers. The Z4 M Roadster follows in the wheel tracks of the 1997 BMW Z3 M Roadster which became a sportting enthusiasts favourite for its dynamic performance, agility, and sportiness.
The BMW Z4 M Roadster will sit alongside a revised Z4 Roadster range featuring new 2.5si and 3.0si models producing 160 kW and 195 kW respectively.
UPGRADE TO NEW ATLAS PLUS
More than 1,500 New Atlas Plus subscribers directly support our journalism, and get access to our premium ad-free site and email newsletter. Join them for just US$19 a year.UPGRADE
More than any other sports car in the world, the BMW Z4 typifies the ideal Roadster.
With its long bonnet, set-back cabin and longitudinally mounted straight-six engine driving the rear wheels, the BMW Z4 Roadster provides a dynamic driving experience to thrill purist sportscar drivers.
The Z4 M Roadster boasts an outstanding high-revving power unit that generates enormous thrust and performance in all speed ranges. The six-cylinder, 3,246 cc, motor develops 252 kW at 7,900 rpm and 365 Nm of torque at 4,900 rpm, and revs as high as 8,000 rpm. The engine produces 78.75 kW/litre (106 bhp/litre) giving the Z4 M Roadster a power-to-weight ratio of 5.6 kg/kW.
The Z4 M Roadster accelerates to 100 km/h from rest in 5.0 seconds and also rushes from 80-120 km/h in 5.0 seconds in fourth gear thanks to its amazing torque.
Fitted with a sports six-speed manual transmission, short throw shifter and M final drive, the Z4 M Roadster delivers fast, crisp acceleration in every gear.
The speed-sensitive variable M differential lock, borrowed from the M3 Coupé, delivers superior driving stability and optimum traction especially when accelerating out of corners.
Stopping the Z4 M Roadster in its tracks is the motorsport-developed BMW M floating compound high-performance brake system as seen in the BMW M3 CSL. The Z4 M Roadster stops in just 34 metres from a speed of 100 km/h.
The Z4 M Roadster uses a bespoke hydraulic power steering set up, delivering knife edge precision and optimum feedback through the quicker ratio rack.
The super sporty Z4 M Roadster boasts easily identifiable external and internal styling features. The front air dam has an X-shaped com¬bination of lines and openings, large air intake scoops, and low-slung kidney grilles as well as two striking feature lines on the bonnet.
Double-spoke design 18-inch light alloy wheels are exclusive to the Z4 M Roadster, while the rear view is dominated by the M trademark quad-pack large bore tailpipes inserted into a horizontal diffuser.
Inside, BMW M instruments have black-faces, white numerals and red needles. The rev counter follows M practice having yellow warm-up warning lights, illuminated while the engine oil comes up to temperature.
The steering wheel, gearshift knob and door sills are specific BMW M items, while the air conditioning, air vent registers and interior door handles are finished in pearl gloss chrome.
Three exterior colours exclusive to BMW M and a wide range of interior trims and add a high de¬gree of individual style for customers.
While the Z4 M Roadster is the highlight of the range, the Z4 family also receives some notable changes for 2006.
The latest VALVETRONIC-equipped double-VANOS magnesium-alloy straight-six engines are fitted to two new models for Australia, the Z4 2.5si and the Z4 3.0si.
The Z4 Roadster 3.0si delivers 195 kW at 6,600 rpm, with 315 Nm of torque available between 2,500 rpm and 4,000 rpm. The engine meets both EU4 and ULEV II emissions standards and accelerates the car to 100 km/h in 5.7 seconds, covering the 80 km/h to 120 km/h run in 5.5 seconds in fourth gear. Top speed is electronically limited to 250 km/h, while fuel consumption in the combined EU cycle is just 8.6-litres/100 km.
The Z4 Roadster 2.5si develops a maximum output of 160 kW and 250 Nm of torque between 2,900 – 4,250 rpm. It will shoot the Z4 Roadster 2.5si to 100 km/h in 6.5 seconds. The muscular engine powers the car from 80 km/h to 120 km/h in just 6.5 seconds in fourth gear. Top speed is 240 km/h and fuel consumption is just 8.4-litres/100 km, while meeting both the EU4 and ULEV II emission standards.
A six-speed manual gearbox is standard across all Z4 Roadster models, while the 2.5si and 3.0si models offer the option of the new BMW Sport Automatic gearbox complete with steering-wheel mounted shift paddles.
Reflecting BMW’s consistent philosophy of continual evolution, the latest generation feature-enhanced Dynamic Stability and Control system comes as standard.
This includes Start-Off Assistance, automatic Brake Fading Compensation and Brake Standby function and auto¬matic Dry Braking.
The integrated Dynamic Traction Control (DTC) function allows drivers to hit one button to improve traction on slippery surfaces. DTC also allows greater slip on the rear wheels whenever appropriate.
On the Z4 M Roadster model, a special configuration of the DSC system allows for the additional slip incorporated in the variable M differential lock.
The Z4 Roadster 2.5si and 3.0si feature BMW’s electromechanical EPS Electric Power Steering. This offers an optimum compromise between feedback and kickback, combined with extra assistance when parking, and a strong self-centring action. Road-speed sensitive Servotronic assistance is also part of the package.
The update also brings larger 17-inch brakes for enhanced stopping power and resistance to fade to the 3.0si model.
The distinctive profile of the BMW Z4 Roadster required little revision at the mid-point of its lifecycle. Exterior freshening changes are modest, limited to a new design for the deeper front air dam, so the car appears to hug the road even more closely.
New front fog lamps and headlight reflectors are matched at the rear by a new taillight design that accentuates the car’s width and enhances its low-down and muscular stance. The interior has been further improved with a more sophisticated look.
All BMW Z4 Roadsters offer plenty of interior storage space with a large glove box, several storage bins, and a 10-litre compartment in the rear bulkhead. Additional boot space is liberated when the power roof, complete with heated glass window, is erect.
The boot can swallow a generous 240-litres of luggage (sufficient for transporting two golf sets) with the roof down and 260-litres roof up. The compact Z-fold roof forms its own tonneau when folded.View gallery - 12 images