Despite not being a fully fledged M model, the top-of-the range Z4 M40i has beaten the M2’s time at the Nürburgring Nordschleife during testing with a lap time below 8min, he said. “The benchmark target during development was the driving dynamics of the M240i. But the car got so good that the benchmark is now M2.”
The entry-level sDrive20i, which will make up half of overall sales volume, uses a 2.0-litre turbocharged petrol with 197bhp and achieves 0-62mph in 6.6sec. The mid-range sDrive30i uses the same engine in a higher state of tune (258bhp) and hits the benchmark sprint in 5.4sec.
The range-topping M40i employs a 340bhp 3.0-litre six-cylinder petrol, has 369lb ft of torque and does 0-62mph in 4.6sec – the same time as its key rival, the Porsche 718 Boxster S. Top speed is 155mph.
The new Z4 is longer, wider and taller than its predecessor, with its width “most notable,” said Ederer. “The wider track goes out by 9cm at the front and 5cm at back. It gives it more stability in corner and makes car look more grown-up.”
The decision to go for a soft-top rather than hard-top was “made in the first six months of development”. Ederer said the decision creates an extra 100 litres of boot space (now 281 litres) over its predecessor, a lower centre of gravity and a better NVH (noise, vibration and harshness) suppression.
The move also gives it a key differentiator with the upcoming, hard-top Toyota Supra, with which the Z4 has been jointly developed.
Improved driving dynamics was the focus of the new Z4, said Ederer, helped by an extremely rigid body structure and chassis mountings, new front and rear axle design and variable sports steering.
An M Sport differential and Adaptive M suspension come as standard on the M40i and are optional on the 20i and 30i. Ederer said: “The sport differential allows you to steer with the rear rather than on the throttle. It’s one of the most exciting things it can do. We always wanted to keep it rear-wheel drive.”
Three trims will be offered in the UK: Sport, M Sport and M Performance, although M Performance will be available on the M40i only.
Pricing is expected to start from £36,000 and rise to £48,500 for the range-topping M40i when the Z4 goes on sale in early 2019.