New BMW Z4 Road Test
Less power but more appeal: the four-cylinder BMW Z4 is an altogether better-balanced package than its big brother...
Now that we’re well acquainted with the long-awaited rear-wheel-drive sportscar collaboration between BMW and Toyota – see our recent test of the Z4 M40i – it’s time to dial things back and see what its mellower four-cylinder stablemate is all about.
While the subjective sentiment around the CAR office is that the punch and snarling timbre of a BMW inline-six has few parallels, in the Z4’s case it actually may not be the best powerplant in this application. The 2,0-litre four-cylinder turbopetrol’s 145 kW may not sound like much, but allied as it is with a useful 320 N.m of torque chiming in at just 1 450 r/min, it feels deceptively punchy. Indeed, the 6,53-second 0-100 km/h sprint time it posted on our test strip managed to raise an eyebrow or two. With peak power available relatively low (4 500 r/min) in the rev range, the engine feels tractable and responds quickly to inputs from the paddle shifters. Consequently, overtaking fast-moving traffic isn’t the hope-and-pray exercise you’d expect.
Even the soundtrack is a pleasant surprise. Granted, it’s never going to hold a candle to the rich baritone of the six-cylinder engine and, roof-up, a portion of it is piped in via the audio system, but there’s still a pleasing thrum emanating from the tail. Nudge the drivetrain-management switch into the sport preset and there’s even the odd thrap and thud crackling from the exhaust interspersed with a spot of turbo hiss when leaning on the throttle.
Said sport mode has its downside, though. While it does sharpen up accelerator response and serves up more aggressive gearshift mapping, it tends to leave the transmission hanging doggedly onto gears, until blipping or flooring the pedal loosens its hold on the cogs. This occasional stubbornness is the only real scuff in the 20i’s otherwise polished and mechanically refined demeanour. Without the pulsing bass of the inline-six filtering into the cabin, it soon becomes apparent the canvas roof isn’t as well sealed from wind and road noise as you’d hope; it even had a couple of us double checking the electric windows were closed all the way.
Other upsides to shedding two cylinders – not to mention some of the M40i’s additional niceties, which we’ll come to a bit later – is a 125 kg reduction in overall kerb weight compared with the six-cylinder car, and the realisation of BMW’s often vaunted 50:50 front-to-rear weight distribution.
The 20i will never trouble the likes of the Porsche 718 Boxster or Alfa Romeo 4C in the handling stakes; in fact, that’s missing the point of this attention-grabbing roadster. This Z4 is more of a tourer which just happens to have dynamic reward woven into its fabric. Without the six-cylinder’s power taxing the chassis, it feels appreciably more poised than its bigger brother. It still has that ability to seemingly pivot about its chassis when the responsive (albeit slightly light) steering is called in to negotiate twisty roads at speed but it doesn’t succumb to the M40i’s touch of nose heaviness when things get really tight. There’s a pleasing fluidity to the way it negotiates sweeping roads and its ride, while not exemplary, is firm but not punishing and the bane of open-top motoring that’s scuttle shake is nearly abolished. Dive into corners and there’s even a degree of playfulness in the chassis, with the 20i showing a willingness to step its tail out in a controllable manner.
There is, however, a blot in its ledger. The M40i gave a couple of us a bit of a skrik in the form of some bump steer that occasionally lurched the car when really pushing it over rippled road surfaces, and that trait has filtered down to the four-cylinder car. Thankfully, with less power feeding those back wheels and a lighter frame which aids in settling laterally distributed weight when straightening out of a turn, this quirk of the chassis doesn’t feel as intimidating as it does in the M40i, but it is there and it’s worth being mindful of it.
Lighter on its feet and with more accessible performance than the six-cylinder model, the 20i is the pick of the current Z4 litter. It’s by no means an affordable car but when viewed alongside the R1 million-plus M40i, it almost seems like a bit of a bargain. That price gap does, however, come at the cost of heated electric seats and PDC to compensate for that long nose and limited rear visibility. Even so, if you’re looking for an attention-grabbing convertible that’s capable of both composed cruising and a little bit of fun on the side, this Z4 could well fit the bill.
Is BMW Z4 number three the one to convince purists it’s a purebred sportscar?
You might not instinctively associate the white and blue roundel with roadsters – not like you would Mercedes-Benz or Porsche, at least – but, since the launch of the Z1 in 1989, the Bavarian brand has featured a Z-roadster in some form or another in its line-up. Following the idiosyncratic Z1 was the first (and thus far only) Z3; the retro-fantastic (and fantastically expensive) Z8; and two generations of the Z4. Neither was especially successful – the first Z4, coded E85, sold 197 950 units, while the second iteration (E89) could muster sales of just 118 444 over its lifetime. As reference, nearly 300 000 units of the Z3 found homes.
BMW AG would therefore feel a touch anxious about the chances of the latest G29-generation Z4 making inroads into a market that’s not exactly flourishing. Does it have the talent to back up its striking new looks and breathe some life into a stagnant segment? Let’s find out.
The result of a technical partnership between BMW and Toyota which also birthed the Supra, the new Z4 sports a box-fresh platform; ditches the complex and heavy folding hard-top in favour of a lighter cloth item stowing in a mere 10 seconds; and has braces and cross members aplenty for 20 percent greater torsional rigidity. And exceptional torsional rigidity allows the engineers to tweak the suspension to their exact liking.
The soft-top has other related benefits, too. Whether it’s raised or lowered, it doesn’t affect the claimed 50:50 weight distribution that’s long been one of BMW’s claims to fame (for the record, we measured 51:49 front to rear); and it takes up far less space when hidden; the unaffected boot measures an entirely sensible 224 litres, just enough for two bulky weekend bags and a few bottles of bubbly.
It also leaves the lines uninterrupted. When raised, the soft-top’s smooth surfacing perfectly mimics a coupé aesthetic. The flagship M40i – there’s an entry-level sDrive20i, too, but no word yet on whether a Z4 M is a possibility – sports double-spoke 19-inch wheels painted in a matte grey to match this test vehicle’s Frozen Grey satin-finish paintwork. This colour combination gives the Z4 an appealingly understated look despite the M Performance body kit’s deep swages fore and aft, and the generously proportioned kidney grille’s conspicuous honeycomb patterning.
Does it look like a BMW, though? Certain elements are unmistakably Bimmer, such as the L-shaped taillamp clusters, but the LED headlamps certainly require some familiarisation – they lack the familiar dual lighting elements that are such a distinctive BMW calling card – and the long front overhang looks awkward from some angles (no surprise given the wheelbase has shrunk 26 mm but overall length has jumped 85 mm). We were disappointed to note some variation in this test unit’s panel gaps, with the bonnet sited just left of centre.
If the exterior of the 4,32-metre roadster doesn’t resoundingly shout BMW, the cabin certainly does. Where previous Z4s boasted bespoke facia designs distinctive from the German brand’s more mainstream fare, the new model’s cockpit bears a strong resemblance to the 3 Series’ design. But that’s scarcely a criticism when the fit and finish are this great, or the facia is this simple to use.
Like the midsize sedan, the Z4 boasts the brand’s new 7.0 operating system, which is as slickly designed and easy to operate as you’d hope. Thankfully, physical climate controls are present and, unlike touchscreen-only interfaces, they allow your eyes to only very briefly stray from the road.
In the M40i, the generously bolstered sport seats are adjusted electrically, and thanks to a lowest setting barely a whisker from the road’s surface, even tall drivers have oodles of headroom. A body 74 mm wider than before also ensures good elbow room. Coupled with the usable boot, the Z4 is a surprisingly accomplished tourer, especially with the roof down when there’s barely a breeze disturbing the calm.
“Tourer” isn’t quite what you’d expect to see in a test of a new Z4, right? Well, that softer edge extends to the ride, too. Combining a newly designed double-joint spring strut at the front and a five-link rear axle, the suspension system is impressively composed across rough surfaces when set to comfort mode. The shortness of the wheelbase is evident at times when the Z4 turns a touch animated on an undulating road, but generally the ride is absorbent and quiet, without feeling loose-limbed.
Punch the sport setting into the Adaptive M Suspension system and a fair degree of rolling comfort is sacrificed for iron-clad body control. Set up thus, on a smooth road the Z4 feels four-square and planted. Certainly, the electric steering system isn’t a shining example of its kind in terms of feel and feedback, but it’s quick and predictably geared off-centre. Owing to the long bonnet and cab-rearward stance, the Z4 creates that typical feeling of pivoting round your hips, eagerly darting into corners before the mellifluous inline-six clears its throat and fires the near-1,6-tonne down the road on a wave of low-end torque and top-end power.
But is it as fun as a 718 Boxster GTS, the highwater mark in this class? No. The Porsche manages to meld searing cross-country pace with an approachable nature that gently goads its driver into going harder and faster. The Z4, conversely, is sometimes intimidating, especially on a bumpy road where traction becomes an issue and the rear-end does a blood-pressure-spiking jump to the left.
Ah, if only the Porsche had the BMW’s engine, though. Usually the highlight of any BMW in which it’s installed, the twin-scroll-turbocharged 3,0-litre is as appealing as ever. Sporting neat round figures of 250 kW and 500 N.m, the latter from 1 600 to 4 500 r/min, the powertrain is smooth, strong and immensely satisfying. Its pairing with ZF’s eight-speed automatic transmission is one of the automotive world’s most harmonious. Despite some traction issues off the line, the Z4 M40i sped to 100 km/h in just 4,83 seconds. The crucial 80 to 120 km/h? Over in 2,99 seconds. This is bordering on M3 territory...
We must mention the M Sport brakes, too. An average time of 2,61 seconds is supercar-beating, with our best stop from 100 km/h a neck-snapping 2,49 seconds.
Is the Z4 a sportscar or a soft-edged roadster? This question remained on the CAR testers’ lips throughout the BMW’s two-week stay in our garage. While it has the engine to bolster its performance-car claim, the overall driving experience just lacks the depth that makes the Boxster a continuously fascinating steer.
Does it matter? We doubt it. What’ll sell the Z4 M40i are its looks and engaging engine. It may be competing in a segment in recession, but it offers an ownership experience distinct from its mid-engined German rival and is a much better car than the aged Mercedes-AMG SLC43.
ROAD TEST SCORE
Z4 BMW Z4 M40i
77 / 100
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