Test Car Specifications
Model tested: BMW Z4 M40i
Pricing: £49,050 for M40i; Z4 starts at £36,990 on-the-road
Engine: 3.0-litre turbocharged straight-six petrol
Transmission: eight-speed automatic, rear-wheel drive
Body style: two-door, two-seat roadster
CO2 emissions: 153g/km (VED Band 151-170: £515 in year one)
Combined economy: 38.2mpg
Top speed: 155mph
0-62mph: 4.6 seconds
Power: 340hp at 5,000-6,500rpm
Torque: 500Nm at 1,600-4,500rpm
Boot space: 281 litres
What's this?
This is the 2019 BMW Z4, offered solely as a two-seat roadster and developed at the same time as the new Toyota Supra coupe in a partnership between the companies. While the previous Z4 featured a folding hardtop, the new Z4 uses a fabric roof that folds away electrically in 10 seconds at speeds of up to 31mph. It helps reduce weight and the centre of gravity, while BMW has worked hard on giving the Z4's suspension a rigid structure to work from - it claims that this is the stiffest open-topped car in torsion that it has ever manufactured.
Kicking off the new line-up is the Z4 sDrive20i, from £36,990, powered by a turbocharged 2.0-litre four-cylinder petrol engine. It produces 197hp and 320Nm of torque for a respectable 6.6-second 0-62mph time, with CO2 emissions as low as 137g/km. There's a price walk of £3,700 to the Z4 sDrive30i, which uses the same basic engine, tuned to 258hp and 400Nm of torque. That helps it drop the 0-62mph time to 5.4 seconds, without altering the official CO2 figure. Both of those models are offered in Sport and M Sport specifications, which are mostly differentiated by aesthetics rather than extra standard equipment.
Topping the range is the car we're driving here, the Z4 M40i. That 'M' signifies its status as an 'M Performance Vehicle' - i.e. one that sits between full-blooded M cars and regular BMWs. Not that BMW has confirmed the future introduction of a Z4M, I might add; it's leaving its options open. The M40i is no half-hearted effort, though, thanks in part to the fact it's the only Z4 with a six-cylinder engine. It's a development of the venerable turbocharged 3.0-litre unit, producing 340hp and a chunky 500Nm of torque from just 1,600rpm.
But that's not the only reason to go for the M40i, which, at £49,050, is nearly £7k more than the Z4 sDrive30i M Sport. No, it also gets the full gamut of chassis trickery as standard, including adaptive damping and an active rear differential. Those can be fitted to the sDrive30i, too, incidentally, as part of the £1,950 M Sport Plus package, so the M40i receives some bespoke styling bits and bobs to set it apart, along with a little more standard equipment. And I mentioned the engine, didn't I? That's arguably worth the premium on its own.
How does it drive?
Let's get the generic Z4 stuff out of the way first. The roof folds quickly and smoothly out of sight allowing unhindered access to the exhaust note behind, but, unless the (optional) wind deflector is in place between the roll hoops and the side windows are raised, the cabin is seriously blowy at anything more than urban speeds. Roof-up, the Z4 is cosy, though there's a noticeable roar from the air passing over the fabric top at motorway speeds. That's an inevitable downside of the material and no different to what you'll find in rival cars.
All versions of the Z4 get what BMW calls 'variable sport steering', which is an electric power steering system that alters the steering ratio and, depending on driving mode and speed, the level of assistance. The variable ratio side of things ensures that the Z4 isn't nervous at high speed in a straight line, yet it keenly nips into corners the more you turn the wheel. There's some useful feedback to your hands, too, though we suspect there would be more if BMW trimmed some fat out of its steering wheel rim...
The straight-six engine is a peach, rumbling away suggestively at lower speeds and then completely letting loose at the top end of the rev counter, doing a good impersonation of a naturally aspirated lump. In Sport Plus mode it's particularly boisterous on the overrun, encouraging you to take control of the gearbox for yourself. All Z4s comes as standard with a new development of BMW's eight-speed auto and as ever it's brilliantly judged, altering shift points and aggressiveness with the driving modes and even allowing the driver to take full command of the gear selection. Gratifyingly, if you have chosen the manual mode, it won't override your gear choice even when the engine is at the limiter. And while this powerplant hardly needs to use all of its revs to give its best, you'll want to hear it at work.
Thankfully, the chassis doesn't stand in the shadow of the excellent powertrain. In its Comfort setting, bump absorption is pretty good, and the car is easy to drive quickly, even in poor weather conditions. The adaptive damping and active rear differential work together to smooth things out, maximising traction without allowing any nervousness into the car. Sure, it's powerful and rear-wheel drive, but it'd take seriously bad driving to get into trouble in this guise.
Rack the settings up to Sport Plus, however, and the Z4 M40i takes on a rather different persona. The damping is firmer, though notably not chiropractor-revenue-favourably firm, but the differential is considerably more aggressive, rotating the car around the driver and into the corners in a highly engaging manner. This is where the Z4 comes alive and while you can turn off the stability control with little fear in the dry, the M40i feels at its best just on the limit of the tyres' considerable grip rather than over it. It's a highly satisfying car to drive quickly, involving the driver, yet doing just enough to make all of the engine's performance exploitable. Good brakes help, too.
Verdict
The new BMW Z4 is not a perfect car, but, in M40i guise, it is genuinely thrilling to drive and yet it can be a relatively civilised long-distance cruiser when needs be. Its looks will divide opinion and we wish it were a little lighter, but there's no denying it's a high-quality offering that certainly demands comparison with the best of its rivals.
Exterior Design
Interior Ambience
Passenger Space
Luggage Space
Safety
Comfort
Driving Dynamics
Powertrain
