Six-pot engine. Dynamic stretch between sportiness and comfort
Mute steering. Oddly proportioned outside and messy digital instruments inside
What is it?
The Z4 has changed. It's become sportier – the old one, with its folding hardtop and cuddly dynamics, took aim mostly at the Mercedes SLK (now SLC). The new one has a fabric top, dropping the weight measurement and centre of gravity. It's evidently having a pop at the Porsche 718, itself in a vulnerable position since the much-lamented departure of that old flat six.
To prove its sporting bent, we're driving a Z4 with an M in its name. Well, a part-way M car, the Z4 M40i. It's got a turbo six with 340bhp. Other engines are four-cylinders in the 30i and 20i.
Ah yes, sporty. Hello internet, the ’Ring time is comfortably under eight minutes. The Z4's physical dimensions are good for hot laps. The wheelbase is shorter than before by a huge 20cm, for agility. The track is much wider, for grip. The body is a whole lot stiffer than the old Z4's, and it's light.
The front suspension, unlike other BMWs, mounts to a special aluminium subframe for precision. Those aren't the only declarations of intent. The Z4 M40i's tyres come from the M4. Its brakes are M-developed too. There's an e-diff between the rear half-shafts. You get the gist.
You can thank Toyota for the existence of the Z4. Toyota wanted a new Supra but didn't have a platform. BMW saw the roadster market softening and wasn't sure if it could sell enough to justify replacing the Z4. But sharing could satisfy the spreadsheet-jockeys. BMW of course is one of the staunchest global holdouts for straight-six engines and rear drive, two articles of faith for a Supra.
So the Supra gets most of the Z4's basic engineering, which is BMW stuff. Engine, suspension and basic platform parts, and electronics too, come from BMW's current set that's used on every longitudinal car they've launched since the 7-er of 2017. The Supra is tuned and set-up differently from the Z4. Both the cars are built at a BMW-overseen line in the Magna plant in Austria.
So if it matters to you that a car has 'brand purity', you'll be wanting the Z4. If you want a roadster, that'll also be the Z4. The Supra, a coupe, plays to a different, JDM-infused vibe. So despite the common rootstock, these cars legitimately appeal to different audiences.
So if there's no hardtop under there, Top Gear wondered aloud to a Z4 designer, why's the tail so bulky? We think unbecomingly so, but we didn't say that. Aerodynamics is the answer. At the other end of the car, the jutting jowls are designed to help capture airflow and usher it past the wheels. If you don't like it, well, lower-spec Z4s have a slimmer front bumper.
Whatever the reasons, a measure of gawkiness afflicts the proportions of this coachwork. TopGear.com's comments section was very unkind about it when we first showed it to you. Seeing it in the metal doesn't help. Shame. You want it to be handsome. Because more than any other kind of car, a roof-down roadster is an item of clothing.
Want to read a long term review on the BMW Z4? Click these blue words.
What's the verdict?
The Z4 has made a big step ahead. Mind you it kept, and improved, the best bit, the straight-six.
The new chassis is properly athletic, able to cover ground in a serious manner. We'd like to feel a bit more engaged with the steering though.
Still, there's a lot to be said for the way it can relax out of a pants-on-fire style and behave with civility for daily use and long motorway hauls. It's practical too.
Style matters in a roadster too. This one? You decide. We reckon many of you already have.