BMW Z4 long-term test: the six-month verdict

Published: 10 March 2020

► CAR lives with a Z4 roadster
► It has six months to impress...
► Can it win us over?

Month 6 living with a BMW Z4: warming to it

Part of the point of a long-term test is to see if a car can change your mind – for better or worse. A car that shines on first acquaintance can become an irksome bag of niggles to live with every day, while a car that initially underwhelms can worm its way into your affections and convert you. This is one of the latter cases.

Winding back to the Z4's first appearance in CAR six months ago, the question was whether or not it could convince as a desirable sports car after a lukewarm reaction at launch. It was a perfectly nice car, sure, but a memorable one, a thrilling one? Nah, not really.

But now the Z4's gone, I really miss it. It's been a great companion.

It's not one stand-out quality that's made the difference (although the 335bhp/369lb ft straight-six certainly helped), more a cumulative total of small, very likeable attributes. The quick-draw roof, the balanced handling (helped by an excellent limited-slip diff), the refinement, the way it's just so easy to jump in and go anywhere, any time, any weather. The styling, which I initially thought awkward, has grown on me too.

It's just a shame the ride quality is so busy. The 19-inch wheels and adaptive dampers handle big bumps well, but there's a constant, gentle jostle on anything other than millpond-smooth roads. On an average dual carriageway it never quite settles down.

Otherwise it would be a near-perfect long-distance car. With plush seats, unstinting equipment (though you'd hope so for £50k) and a news-anchor-smooth manner, the Z4 feels very much like a grand tourer in miniature. It even has a decent boot (one that's carried all sorts, from musical instruments to garden rubbish, during its time on the CAR fleet). Other than a few absent seats, you could almost be driving a 3-series. Which is a double-edged compliment. I drove a Porsche 718 Boxster, the Z4's express benchmark, not long before the end of the BMW's time with us, and the Porsche is unquestionably more involving and rewarding – more of a sports car to the Z4's roadster. But the Z4 isn't as far behind it for enjoyment as I'd thought it would be in isolation. And driven back-to-back, the BMW's engine makes the 718's four-pot feel particularly lacking.

Z4 rear quarter

Any niggles? A few. Keyless entry wasn't a policy that always applied to the boot, which would occasionally sound the alarm if you opened it without first plipping the keyfob; the sat-nav frequently lost track of the Z4's position, believing it to be ploughing through fields and buildings a quarter of a mile or so to the side of its actual co-ordinates; and the moulding around the drive mode switch would expand in hot weather and get stuck down when depressed, needing to be freed up again by hand. This seemingly fixed itself over time (that or nature fixed it via the onset of autumn). And there was the recalcitrant windscreen wiper connection mentioned in Month 2. But I still really enjoyed life with the Z4, mostly because it fitted in so neatly. The first time I pulled onto my drive in something else I felt an odd pang of pining. So it's done its job.

I understand why people aren't struck by the Z4 initially, because I was one of them. It's not a car you'd set an early alarm to take the long way to work for, and other sports cars (718, A110 and the platform-cousin Supra too, for my money) are more exciting. But it is good fun, it's remarkably easy to live with and driving one every day can make you feel, if not thrilled, then quietly contented. And there's plenty to be said for that.

By James Taylor

Logbook: BMW Z4 M40i

Price £49,185 (£53,865 as tested) 
Performance 2998cc turbo straight-six, 335bhp, 4.6sec 0-62mph, 155mph  
Efficiency 33.2mpg (official) 29.5mpg (tested), 165g/km CO2 
Energy cost 20.0p per mile 
Miles this month 1549
Total miles 9756

Month 5 living with a BMW Z4: seeing double

BMW Z4 twins

One of the most convincing factors in my steadily growing affection for the Z4 is its super-lungs straight-six. When you take that powerplant away, how does the car left behind stack up?

To find out, a quick back-to-back with this Z4 20i base model, which loses one litre, two cylinders and around 140bhp (and 130kg) but starts at £37,115, a serious saving on our M40i's £49k pre-options price.

That said, this red 20i is fitted with a dusting of options, winding its price to £44,655. It has the same 19-inch wheels and adaptive dampers as our car, but the 20i still suffers from the same slightly busy ride quality, not helped by being a lighter car. It's comfy but with a constant patter.

You do feel the reduction of metal in the engine bay through lighter, slightly faster steering response, and the handling's nicely balanced, if still not a Boxster-beater. It makes a nicely throaty sound, and performance feels ample up to a point – specifically, the point when I pulled out to overtake, realised I was 133lb ft shorter than usual and thought better of it.

Taking away the straight-six leaves an extremely well-rounded car, with many of the virtues of our M40i, if not its thumping performance and clever diff. I'd be lying if I said I enjoyed it as much as the M40i but it got close, at a much lower price. I suspect a well-optioned 30i might be the pick of the range.

By James Taylor

Logbook: BMW Z4 M40i

Price £49,185 (£53,865 as tested) 
Performance 2998cc turbo straight-six, 335bhp, 4.6sec 0-62mph, 155mph  
Efficiency 33.2mpg (official) 29.5mpg (tested), 165g/km CO2 
Energy cost 20.0p per mile 
Miles this month 1549
Total miles 9756

Month 4 living with a BMW Z4: the CAR reader test

You drive our BMW Z4

Some music is better after a couple of listens; some films need a second watch. I think the Z4 M40i might be the same. Maybe our independent panel – a BMW owner, an engineer and a racing driver – can help me work it out for sure.

Neil Brightman: 'It's a very smooth engine - what BMW is best at'

A development engineer for an automotive engineering company, Neil Brightman is perfectly placed to judge a car. He's tough to impress but the Z4 makes a good first impression. 'The ride is very controlled considering we're driving on uneven roads. You can almost feel the [electronically controlled] dampers soften as they hit a bump. In fact, if you concentrate, you can actually hear them operating with the roof down' – a faint fshh sound I hadn't noticed previously.

That's testament to the Z4's roof-down refinement. 'It's not a warm day but you barely notice the roof is down. It's more claustrophobic with the roof up; the low silhouette means it feels hunkered around your head.'

Like me, Neil finds all-round visibility isn't the Z4's strongest suit. 'The usual blindspot in the big A-pillars isn't helped by the tweeter speaker surrounds, which block my vision even further.'

He enjoys the straight-six's power delivery and turbocharged torque, and the smooth-shifting ZF auto 'box: 'It doesn't feel as rapid as a dual-clutch, but you wouldn't be changing gear any quicker in a manual anyhow' – except on the couple of occasions he requests an upshift on the paddle with no response.

He's not a fan of the steering wheel. 'Why is it so chunky? It feels like my fingers are wedged between the paddles and the spokes.'
Overall? 'It's very nice – but it's £50k. For an out-and-out sports car it doesn't feel quite direct enough. I think if I were buying new, I'd be drawn to a Porsche Cayman. Or I'd get the same engine in a used 4-series for a little less.'

Ryan Lindsay: 'Planted under braking, and the diff hooks up nicely'

Ryan Lindsay is no stranger to time behind the wheel of a Z4, albeit one with slick tyres and a gigantic rear wing, having raced a Z4 GT3 to multiple podiums in the Britcar endurance series. He's also logged plenty of flying hours in all kinds of M cars as a track instructor.

The Z4 ticks a big box as soon as Ryan climbs in. 'The seat can be positioned very low for a production car, and your legs are pretty straight, without much of a bend in the knee – you feel like you're in a proper sports car.'

Z4 LTT front cornering

Guiding the Z4 smoothly and accurately around my B-road loop, Ryan downloads his first impressions: 'The gearbox shifts so smoothly. Far more so than an M3's 'box – that's quite abrupt.'

He can feel the effect of the Z4's fat tyres: 'The steering pulls around a bit over bumps, which probably shouldn't be a surprise when they're 255mm wide. It feels very planted overall, though.'

Ryan's impressed with the electronically controlled differential. 'It hooks up nicely, without being over-eager. The car's traction is really impressive, actually. The 275s on the back help, of course...'

Also scoring points with Ryan are the straight-six's tone, the head-up display's built-in shift lights, and the wireless Apple CarPlay – although the voice recognition system seems to misunderstand him just as comprehensively as it does me...

Nick Corney: 'I was expecting it to be more sports car-esque'

Nick Corney has a headstart on me: he's been driving a rear-wheel-drive BMW with practically the same engine as the Z4 for two and a half years. The business owner and musician's 440i has a touch less power than the Z4 M40i's 335bhp six, but it's an earlier evolution of the same engine (that's the B58, engine code fans).

'The exhaust system sounds more prominent than my car.' And in Sport mode, it 'sounds almost like a V8', he says.

Z4 LTT engine talk

The throttle response is keener than in his 440i: 'Even in default Comfort mode, it's more responsive.' When he ups the pace in the Z4, it responds with a lunge of acceleration and a shimmy of oversteer. 'Not bad, is it?' he smiles. 'In my car we wouldn't have felt quite such a kick as that.

'Overall, it doesn't feel as different from the 4-series as I'd thought it might. I was expecting it to be a little more sports car-esque. It's pleasant but it's not a joy – but with more time in the car that might change.'

I know exactly what he means, because at the start of my time with the Z4 that's exactly how I felt. I'm convinced more than ever that the Z4 is a car that needs a little soak time to fully appreciate.

By James Taylor

Logbook: BMW Z4 M40i

Price £49,185 (£53,865 as tested) 
Performance 2998cc turbo straight-six, 335bhp, 4.6sec 0-62mph, 155mph  
Efficiency 33.2mpg (official) 20.1mpg (tested), 165g/km CO2 
Energy cost 29.4p per mile 
Miles this month 1092
Total miles 8207

Month 3 living with a BMW Z4: is it better than a Toyota Supra?

Z4 LTT vs Supra

Not relevant. That’s what senior folk at BMW and Toyota say when you raise the question of which is more fun to drive, Z4 or Supra. While the two cars were co-engineered, and share the vast majority of their hardware, and are built at the same factory in Austria, they’re chasing different markets.

The Supra’s engineering chief Tetsuya Tada says Toyota developed the car to compete with the Porsche 718 Cayman (the sports car Toyota considers the class benchmark), while BMW configured the Z4 to rival the 718 Boxster. 

But it’s a natural question that people are going to ask nonetheless, so here’s my best answer. I believe the Supra rides, handles and entertains better than the Z4. 

While the two cars share the same suspension and powertrain, the fine-tuning of both is separate. The Toyota has its own settings for the electric power steering, active dampers and electronically controlled differential, and it’s their calibration that gives the Supra its different character. The steering feels more measured, less darty, than the Z4’s, and its overall balance feels more malleable at the limit. Its ride quality is smoother too – perhaps a result of its fixed roof as well as its suspension tuning. An overly busy ride is one of the Z4’s bugbears – it never quite settles down, and in that respect the Supra is the comfier car.

The Z4 has an array of drive modes, from Comfort to Sport to Sport+, but the Supra simply has one big Sport mode button, and feels the better for it – although you can individually fine-tune steering, damping, diff and engine maps in a further menu. 

Overall, however, the two cars feel – surprise, surprise – very similar. So much so that when I climbed back into the Z4 I found myself air-pressing phantom switchgear that had moved position from its location in the Supra. 

The interiors share plenty of common parts and architecture but they’re less alike than pictures suggest. The Z4’s is more luxurious, and I believe has superior ergonomics, cluttered digital instruments apart; the Supra’s feels cheaper and gloomier, but with its central tacho it also feels more like a proper sports car cockpit as opposed to a convertible 3-series. I find its seats – almost the same, but not quite – a touch comfier, too. 

Subjectively, I’m not convinced either is a great-looking car – while the short-wheelbase and wide-track proportions help agility they don’t lend themselves to beauty – but I find the Supra’s mini-Dodge Viper styling a bit more appealing than the Z4’s stumpier soft-top aesthetic.

Despite all this praise pointed the Supra’s way, I really am enjoying the Z4. If it’s not quite as involving as the Toyota, it’s not far off. The Supra wins this sibling scrap for me but I’m warming to the Z4 with every drive. Besides, actually, my favourite sports car that uses the same engine is the Morgan Plus Six…

By James Taylor

Month 2 of our BMW Z4 long-term test: a windscreen wiper fault

BMW Z4 windscreen wiper fault

The Z4 had already been here at CAR for a couple of weeks before I could actually get behind its wheel for the first time. Other people had been having a fine old time in the BMW roadster, but my time in it got off to a terrible start: at the first press of the ignition button a message flashed up on the iDrive screen warning of a windscreen wiper fault.

I adopted my tried-and-tested strategy in the event of any kind of error message, which is to ignore it and fervently hope that it goes away by itself. Halfway home, it did.

Next morning, however, the message was back and wasn't budging, just like the steady rainfall that had set in for the day. There was no response from the wipers whichever position the stalk was in, so I abandoned ship from the BMW and drove a more reliable MGF to work instead (not a sentence you hear every day).

The local BMW dealer, Sycamore Peterborough, was very busy and so was I, and with more rain on the way my already-flimsy resolve for investigative consumer journalism deserted me and I called BMW's press office for speedier help. The Z4 went away to the workshop for diagnosis, and the fault transpired to be a loose connection, a straightforward fix.

Before I got my Jonah's hands on it, the Z4 had already been busy at CAR, pressed into service in the July issue's Shortlist feature where it didn't fare too favourably against the Toyota Supra (its non-identical twin), the Alpine A110 and the Porsche 718, storming to an emphatic fourth place.

But that first drive before the rains came was a pleasant one – roof down, stereo on, straight-six turning lazily in eighth gear – leading me to suspect the Z4's strongest appeal may be found at low speeds rather than high. It's been an atypical scenario, having a sports car and not driving it, but I've been making the most of it (and the sunshine, bordering on heatwave) since its return. More in-depth driving impressions soon.

By James Taylor

Logbook: BMW Z4 M40i

Price £49,185 (£53,865 as tested) 
Performance 2998cc turbo straight-six, 335bhp, 4.6sec 0-62mph, 155mph  
Efficiency 33.2mpg (official) 30.0mpg (tested), 165g/km CO2 
Energy cost 20.9p per mile 
Miles this month 1439
Total miles 6185

Month 1 living with a BMW Z4 M40i: hello and welcome

Z4 rear quarter

Here's a second chance to make a first impression. When I first drove the Z4 at its launch in October last year, it was a good car but not an exciting one. It felt more like a saloon that happened to have two seats and a soft-top than a spine-
tingling sports car. I've been wondering if I judged it harshly, especially after enjoying driving its closely related, co-engineered Toyota Supra platform-mate recently. Now the Z4's got an entire British summer (and a bit of autumn too) to argue its case.

The Z4 range starts at £37,115 for the 20i model, with a 196bhp 2.0-litre four-cylinder engine, or £40,815 for the same engine hopped up to 256bhp in the 30i. This car, however, is the range-topping Z4 M40i, with a musclebound 3.0-litre turbocharged straight-six under its stubby bonnet.

Compared with the rest of the range, the M40i also gets larger 19-inch wheels (with tyres essentially the same as those fitted to the current M3/M4), adaptive dampers (optional on 2.0-litre cars) and an active diff, as also fitted to the Supra. Less dynamic niceties include electrically adjustable seats with leather-meets-alcantara upholstery and extra aluminium trim compared with lowlier models.

Our car's also got a fancy paintjob, the optional Frozen Grey II metallic matt paint priced at £1880. In addition to the paint there's a further £3450 of options: the £900 Visibility Package (adaptive LED headlights and automatic high-beam assist); the £750 Comfort Package (heated steering wheel, wind deflector, keyless entry and start, and a through-load serving hatch from boot to interior); and the £1800 Technology Package (head-up display, Harman Kardon surround-sound speaker system, wireless phone charging, rear-view parking camera and automatic parking assistant).

Z4 LTT front cornering

So many of the ingredients are there for a truly great sports car – engine set back for a 50:50 weight distribution, short wheelbase for agility, wide track for stability, clever diff and great throttle response by any standards, not just for a turbocharged engine.

Maybe a bit of extra soak-time will help the Z4's true character shine. I'm looking forward to getting to know it again over the coming months, and finding out if it can thrill as well as cosset.

The Z4 has traditionally been more about sun-dappled boulevard cruising, rather than being a car to inspire an early alarm and the long, twisty way to work. Here's hoping this one's both.

By James Taylor

Logbook: BMW Z4 M40i

Price £49,185 (£53,865 as tested) 
Performance 2998cc turbo straight-six, 335bhp, 4.6sec 0-62mph, 155mph  
Efficiency 33.2mpg (official) 31.3mpg (tested), 165g/km CO2 
Energy cost 18.3p per mile 
Miles this month 299
Total miles 4746

By James Taylor

CAR's deputy features editor, occasional racer