This is BMW's sister car to the Toyota Supra. It's a roadster, and an actual canvas one rather than the old folding hard-top. Most of the mechanical bits and electronics are drawn from BMW's shelves (and the Supra will be the same under the skin although differently set up).
The wheelbase is much shorter than any other BMW to make it agile, and there's a unique aluminium subframe to make the front suspension more precise.
The test car is the M40i, outfitted with all the right six-cylinder power and various M parts in the brakes. Like all the new Z4s, it's only available with the eight-speed auto.
Other engines on offer are the 20i with 145kW or the 30i with 190kW. They're the same 2.0-litre four with different degrees of turbo puff. Even the slowest gets to 100km/h in 6.6 seconds.
WHAT'S THE INTERIOR LIKE?
As a sports car, there are some things the Z4 needs to get right in its cabin. It nails them too. First, you sit nice and low, cocooned between the sill and transmission tunnel, in a seat that's well-shaped to support you, and widely adjustable too. It's a design of seat specific to the car, not just yanked out of some saloon.
There's a bit of storage space behind the seats, and a box with a door back there, plus a few small pockets around the cabin. But you're going to be relying on the boot, and at 281 litres it's not a bad size – far bigger than an MX5's. It also stays the same when the roof drops, whereas folding hardtops eat boot when you drop them.
Roof up, you get a mild shimmy of wind noise compared with a saloon at 100-plus, but it's completely sealed against wet and cold, so it feels no sacrifice having a tent not a steel box over your head.
Lowering or raising the top is an all-electric job that troubles just one finger. It needs only 10 seconds, and can be done at anything up to 50km/h. Roof down, turbulence is well-managed. With the side windows up there's not enough rustle to need more than a couple of extra notches of stereo volume. A neat little plastic net clips between the two rollover bars and further reduces the buffet. If there's a winter nip in the air, the heated seats do their job.
As a BMW it's just what you'd expect. The usual new-generation of iDive, the usual high-quality plastics and trim. The usual positive and well-sited switches, the usual slightly too fat steering wheel.
WHAT'S THE INFOTAINMENT LIKE?
The system is what BMW calls iDrive 7.0. It's a fairly big change over the old iDrive generations, including new central screen graphics and design, and a screen in place of real instruments. As far as I'm concerned, the .0 is important. It has brought in some new wrinkles, which need addressing in a future 7.1.
For instance, and this matters on a sports car, the rev counter is almost illegible – a silly shape, with a small red needle chasing around on a red background. And between the rev counter and the speedo is an area used for navigation instructions. If you know where you're going, you can't switch it to any other read-out. So that other info – music, or a power gauge, go in the middle of the rev-counter, further confusing its graphics.
Also some of the new 'metal' controls for the climate and vents are obviously fake, and their markings are illegible when backlit. Still, BMW has at least kept the rotary controller and fixed shortcut buttons, unlike Audi. And the tile interfaces on the high-res screen work well.
The head-up display on the test car is ripper, and the stereo – an optional Harman Kardon on the tester – is well listenable. Maps have clear traffic via a built-in SIM card, or you can use Apple CarPlay.
WHAT'S THE PERFORMANCE LIKE?
BMW swears there will be no full-on Z4M in this generation, but with track lap times close to the M2's and a zero-to-100 of 4.6 seconds, I reckon the M40i will do.
The engine pelts beyond 6500 when you have space to stretch its legs, never easing off the pull. Urgent but sweet layers of harmonics, all the better when the roof is down, liven up the experience some more.
Usually the autobox arranges things well, darting between the gears appropriately, and of course you can choose any number of programmes, from low-rev/high-gear 'eco pro' to a more urgent 'sport' and 'sport +'. But if you do get stuck at low revs there's a little turbo lag to wait for. I drove it mostly in manual mode using the paddles, because it's a sports car and I like to be involved.
Going more gently, the engine slips into a much quieter frame of mind, so you can waft about unobtrusively.
WHAT'S IT LIKE ON THE ROAD?
This is one of those cars that seems to pivot around a bend, rather than having to lean and stress. The font end, a long way ahead of you, swings willingly into the corner, and the steering ratio gets faster as you move away from the straightahead, so it's easy to tighten your line.
Then you can force some effort into the back tyres with a dose of turbo action, and it generally just digs in and catapults you away. An electronically controlled differential is standard: you really can feel it making the tyres work to their limits. In fact you get more sense of the car working for its living from your backside than from the slightly numb steering.
The engineers make a fuss about the grip the 40i can show in corners, and they're not wrong. It's also got a load of discipline in chasing down any undue body float or lean: click the dampers into sport mode and everything is locked down a treat
But as with the powertrain, there's another side to the chassis. It'll mooch as well as hoon. The dampers will soften off in gentle running, and then the suspension balms your backside with a genuinely pliant ride.
WHAT ABOUT THE SAFETY FEATURES?
One of the benefits of getting your sports car from a full-line German maker, rather than an industry minnow, is that all the expensive-to-develop electronic systems are in place. And even if there's no independent crash-test yet, BMW isn't in the habit of mucking up the structures of its cars. Collision braking (that sees vehicles, pedestrians and cyclists) is standard, as is lane departure warning.
Active cruise is optional, with a measure of steering support on highways. The forward camera will read speed limit signs and the system prompts you so that with a single button-press you can have the cruise control obey them. It'll also warn you of other signs like no entry. That option pack includes blind-spot warning and reversing cross-traffic warning.
A rear camera is standard, which seems like overkill on a smallish roadster, but could be useful when the roof is up. You can also get BMW's excellent adaptive LED matrix headlights.
SO, WHAT DO WE THINK?
If you like engines, this six-pot gives the Z4 M40i a distinct advantage over the Porsche 718. If sharp steering matters to you, the Porsche still has the edge. For an even more vivd driving experience, the new Alpine A110 clearly gets the nod.
But as an all-round speedy sportster with an ability to do the everyday chores and enjoy a hit of sunshine, the Z4 is hard to beat.
Words by Paul Horrell
2018 BMW Z4 M40i (European spec)
Price N/A WARRANTY 3 years/unlimited km Engine 3.0L petrol turbo straight six Power 250kW at 5000-6500rpm Torque 500Nm at 1600-5000rpm Transmission 8-speed auto Drive rear-wheel drive Body 4324mm (l); 1864mm (w exc mirrors); 2024mm (w inc mirrors); 1304mm (h) Turning circle 11.0m Towing weight NAkg Kerb weight 1535kg Seats 2 Fuel tank 52 litres Spare no Thirst 7.2 l/100km combined cycle