What is it?
Previously pitched on the strength of its styling and sporting on-road attributes, this time around the BMW Z4 is being sold on its sophistication and added comfort. This move pitches it towards the Mercedes-Benz SLK and away from the Porsche Boxster.
The big news for the BMW Z4 is the adoption of a folding hard-top roof. BMW says the switch from fabric is in response to requests from customers. Accommodating the roof, which retracts in 20sec, has altered the dimensions of the Z4; the new model is 148mm longer and 46mm wider than before. But as the new roof boasts a flatter turret, the car’s height has been trimmed by 8mm, at 1291mm.
What’s it like?
Three versions of BMW’s classic straight-six engine will be offered with the new Z4. They include an entry-level 201bhp 2.5 litre with 184lb ft of torque in the sDrive23i, and a 255bhp 3.0 litre with 310lb ft in the sDrive30i. Our test car, however, was fitted with the range-topping twin-turbocharged 3.0 litre serving up 302bhp and a gutsy 295lb ft. All three models come with a six-speed manual gearbox, but BMW expects the optional six-speed automatic and the seven-speed double-clutch unit (as fitted to our test car) to prove most popular.
Despite weighing 1580kg (270kg more than the previous model), the sDrive35i has plenty of punch off the line and through the gears. It hits 62mph in 5.1sec and a limited 155mph, figures that make it quicker up the strip than a Boxster S.
The only real disappointment is the sound. With a pair of turbos muffling the induction and exhaust, it is hardly alluring.
The Z4’s wheelbase remains virtually unchanged at 2496mm, but its tracks have grown. It is all topped off by standard 17-inch wheels, but our test car ran on 19-inch alloys.
The optional wheels fill out the arches to great effect – especially when combined with the optional M-sport suspension package that lowers ride height by 10mm – but they do nothing for the overall balance. There’s little in the way of on-the-limit adjustability when you dial up sport plus mode to delay the onset of DSC (dynamic stability control); you get entirely predictable understeer, followed by the onset of roll oversteer at the rear when you step away from the throttle in constant-radius corners. It is foolproof but lacking in excitement. We suspect that 17-inchers will be the way to go.
The steering is also not without fault. The Z4 sticks with an electro-mechanical set-up. A 14.4:1 ratio replaces the 14.2:1 of old and there are changes to the positioning of the rack. At 2.7 turns lock to lock it is not quick, but it is reasonably alert off centre. The major problem, however, remains a lack of feel. With the car set in normal mode, it is rather light. Switch into sport and/or sport plus and the weighting increases.
The ride is far better resolved, for the new Z4 has traded some of its renowned body control for a touch of added comfort. Body control remains impressive, but the primary ride has improved greatly, with a more composed action over a variety of surfaces. The roadster’s steel structure also resists scuttle shake with authority, even on badly pockmarked roads.
On the motorway with its roof up, the Z4 is much more refined than before. A larger rear window and rear quarter windows (that can be opened) also provide added visibility. The boot is also a useful 50 litres larger, too, at 310 litres.