The Z4 is a talented roadster with much in its favour, just don’t expect Boxster levels of tactility

The Z4 has always been a BMW that’s had a little bit of a personality crisis, never being fully clear as to its purpose in life. The first generation wasn’t a bad car at all, but it couldn’t manage to knock the Porsche Boxster from its perch as the driver’s roadster of choice.

BMW’s second stab at it was an altogether softer machine. Again, not a bad car, but not an overtly sporting one either, even in range-topping sDrive35iS guise. No, this was a machine that was aimed at the TT and SLK rather than the Boxster, and as a drop-top cruiser it was a fine piece of kit provided you didn’t ask too many questions of its chassis.

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But what should we expect from this latest, G29 generation of Z4? BMW’s billed it as having been engineered with a focus on maximum agility, dynamism and steering precision yet in almost the same breath admits that if you’re looking for the ultimate driving experience then the Boxster is the way to go. In truth though, the vast majority of Z4s sold in the UK will be of the 20i variety, pitching it against slightly more mundane offerings from Mercedes-Benz and Audi and perhaps tempting buyers away from a top-of-the-range Mazda MX-5.

And the Z4 does have a lot going for it; good (if a little gawky from some angles) looks, a relatively entertaining drive, good engines offering a blend of performance and economy, and a host of standard equipment. It’s an undemanding car to drive, offering precise steering, huge levels of grip and a balanced chassis, but it’s somewhat one-dimensional, lacking any layers in its performance and delivery. It’s easy to drive fast and for the most part very composed when doing it, but you’d be having more fun in that MX-5 or Boxster.

For many owners the lure of a reasonably priced BMW roadster will be enough – stylish, quick and easy to drive and with all the gadgets and gizmos you could possibly need. If you’re happy to swan about the countryside roof down taking in the sights and smells it’s a good choice, just don’t expect it to be the last word in dynamic ability or tactility.

Performance and 0-100 time

The Z4’s certainly quick, with even the entry-level 144kW 20i model accelerating from 0 to 62mph in 6.6sec, which is perfectly acceptable, especially when you take into account its 1405kg kerb weight. Two-door roadster it maybe, but the Z4’s no lightweight. Opt for the 30i model, which uses the same engine as the 20i but in a different state of tune, developing 189kW, and that time drops to just 5.4sec.

Naturally enough, it’s the range-topping M-lite M40i that’s the most rapid, thanks to its 250kW turbocharged straight-six. With a 4.5sec 0-62mph time, it’s quicker than a PDK 718 Boxster and just 0.1sec behind a similarly equipped Boxster S.

> Click here for our review of the Mazda MX-5

Where the 20i is brisk, rather than outright fast, the 30i does feel considerably quicker, especially in the mid-range, but there’s no doubt the M40i is the one that is distinctly rapid. On dry roads it hooks up astonishingly well, and feels every bit as quick as its figures suggest.

Ride and handling

On first acquaintance the Z4 can seem like a far too refined proposition; it’s by no means a demanding car to drive and unless you delve into its various drive configurations you could be left with the impression that it’s a junior exec masquerading as a sporting roadster. Push it harder and it certainly improves, with further layers of ability, but it’s nowhere near as sharp a driving tool as a Boxster.

In part, this sophisticated nature is down to the Z4’s incredibly stiff structure – there’s nary a shimmer or a hint of flex, even when travelling over rough surfaces. The Sport and M Sport models (20i and 30i only) have less rubber on the road than the M40i and the Sport has a suspension set-up that’s slightly softer too. As a result, it’s the Sport model that seems to be the most playful, with steering that’s slightly more communicative, and while grip levels are slightly lower, it’s a more interactive machine than the arguably overtyred M40i. The Sport model rides better than the M Sport, but the latter is by no means too harsh for everyday driving.

The M40i adds a significant amount of kit to its armoury – 19-inch wheels with wider tyres, adaptive M dampers and a limited-slip differential. The grip it can generate is quite phenomenal, and while the variable sport steering (standard on all Z4s) is accurate and direct, it gives very little impression of what the front tyres are up to. The rear is similarly planted, but other than the scenery passing at a quicker rate of knots, there’s not a huge sensation of speed or involvement.

BMW says the M40i is faster than the M2 Competition round the Nürburgring and we can believe that, as it’s very composed when being driven quickly. There’s just a lack of joie de vivre in the way it goes about its business. Quick, undoubtedly, just not enthralling or involving. BOB HARPER