Porsche 911 vs BMW Z4

What's the difference?

The more things change, the more they stay the same. The t-hybrid might be an entirely new propulsion system for the 911, but the net result is unchanged – power, poise and performance on tap.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

The Z4 didn’t make me feel like Peirce Brosnan’s 007. It’s way too serious – a proper gritty reboot. Maybe it’s meant for Daniel Craig. Either way, its brave design makes it one of the best-looking BMWs of recent memory, and it’s a tech- and comfort-fest that the Bavarian automaker should be proud of. I just wish it was a smidge more fun behind the wheel.

This facelift debuts a revolutionary exterior design that has completely reshaped the 911.

Just kidding. If it ain’t broke and all that. The front air vents and exhaust have changed, the former now an active intake system that deploys via vertical flaps, but elsewhere it’s largely evolution over revolution.

Instead, Porsche has focused most of the updates in then cabin. In here, you’ll find a new digital instrument panel, they’ve changed some of the levers and the steering wheel.

In true Porsche fashion, though, this new 911 mimics the older versions in that it's one of the more intuitive cabins you’ll ever sit in. Everything feels as though it’s exactly where it should be, and all feels entirely centred on the driver.

The Z4 is a sight to behold. It’s brave, especially for a BMW, it even betrays the brand’s strongest styling pillars, making its own way with its more horizontal grille design, flat body and curved out rear.

It’s more than that, though. In black, this car looks sinister, brooding. The more you look at it, the more you notice tiny details - the scooped-out sides, or the way the entire rear seems to flick up into the integrated spoiler. I couldn’t get enough of staring at it – it manages to look even better with the roof down.

That’s probably when it hit me. To my eyes, at least, this is the most stunning BMW in years. Sure, the X7 is a sight to behold due to its sheer dimensions and borderline offensive grille, but the Z4 is the opposite. It’s subtle, it hides its details away in its silhouette.

It’s designer, Calvin Luk (an Australian no less), was inspired at least in part by the Z8 – another Brosnan bond car – and you can see the Fisker design reflected in the Z4’s low, flat grille and almost bulbous rear.

Inside, sadly, the Z4’s strong design doesn’t quite play out. There’s no wily Fisker touches here, just a standard set of BMW switchgear. While it all works well, it just dumbs down the Z4’s character.

The big, chunky steering wheel in particular is a let-down. It’s the same wheel that sits in the brand’s X5 SUV, and it feels right there, but not here in a convertible where you’re so close to the ground. A smaller wheel would not only suit this car better, it would make it feel just a smidge more alive. I miss the three-spoke M sport wheel from previous-generation BMW cars.

I do like the dash, which is seemly carved from rhomboid shapes - a theme that rolls into the doors, screens, and vents elegantly. I’m normally not a fan of gloss plastics and chrome touches, but in the Z4 they’re all tastefully applied.

The seats, too, are lovely. I’m not sure about the contrast bright-red leather our car came with, but they’re nice and close to the ground and have excellent trim that you seem to sink into just enough to be comfortable and sporty all at once.

It’s a slick place to be, I just wish it felt less like you were at the helm of an SUV and more like you were driving something that looks this damn good.

This probably falls under the ‘next question, please’ umbrella, given that, while the Porsche 911 is known for a lot of things, vast acres of space with loads of practicality perks just ain’t a part of its portfolio.

The new 911 measures a not-insubstantial 4533mm in length, 1852mm width and around 1294mm in height, and it rides on a 2450mm wheelbase. Luggage space is a paltry 135 litres under the bonnet, plus whatever else you can fit in your pockets.

There’s seating for four, should you not like the people you’re squeezing back there very much, but really the 911 is best enjoyed as a two-seat proposition – which is why you can also delete the backseat, should you wish.

It also weighs a minimum 1595kg, or up to 1745kg, but Porsche says the hybrid tech only adds about 50kg to the total kerb weight.

The Z4 is a convertible, so it’s naturally compromised on space. As far as convertibles go though, you’ll be hard pressed to find one you can fit more stuff into.

The Z4 is wide - the same width, in fact, as a 5 Series - and this carries into the cabin. There are only two seats, but those seats are wide, and occupants will find themselves with luxurious amounts of airspace for their arms, as well as excellent leather-trimmed and padded surfaces for landing elbows on.

Legroom is also great, as the seats have a surprising amount of rail-travel on them, so that even taller folk won’t struggle to fit their limbs in.

A genuinely impressive characteristic of the Z4 is much head room there it is. Despite its low-slung looks from the outside, the roof towers over my 182cm tall head when I’m inside, so this isn’t one of those convertibles that feels like braking too hard might simply decapitate those above six-foot tall.

In terms of storage areas you get some long but shallow trenches in the doors, a bay with connection ports and a Qi wireless charging pad under the air-conditioning controls, a glovebox (hey, not all convertibles have them) and a trick centre console that houses two deep cupholders inside.

There’s also a netted shelf behind the seats that could fit small bags, and given the length of the cabin, you could even fit laptops and the like behind the seats provided you haven’t used the full extent of the seat’s rearward movement.

The boot is deep, wide and long for a drop-top, and offers a total of 281-litres which is more than some popular hatchbacks. It even offers tie-down points and netting either side. To top it off, the fabric roof folds away into its own compartment, so the boot space is unaffected if you choose to drop the lid.

For a convertible – the Z4 is a practicality wizard.

The Z4 isn’t cheap, but it plays in a field of expensive Deutsche drop-tops. Our car was the mid-spec 30i which comes in at an MSRP of $104,900 (before on-road costs).

For that you’ll get a more highly tuned version of the base 20i’s four-cylinder turbocharged engine, producing 190kW/400Nm, 19-inch alloy wheels, M Sport brakes, Adaptive M suspension, and adaptive LED headlights.

That’s on top of the already impressively-specified 20i’s kit which includes dual 10.25-inch screens – one for the multimedia functions, the other as a digital dashboard, a head-up display, full Vernasca leather interior trim, auto-dimming rearview mirror, power adjustable and heated front seats with memory function, dual-zone climate control, 10-speaker 205W stereo, a Qi wireless charging pad, and adaptive cruise control as part of a marginally upgraded safety package (more on that in the safety section).

It’s a pretty plush set of equipment, although a challenging value proposition as the almost-as-well-equipped 20i starts from $84,900, a full $20k cheaper.

Rivals for this 30i model? You’ve got the soon-to-be-discontinued Mercedes-Benz SLC300 ($102,500), all-wheel drive Audi TT S quattro ($105,661), and, at a stretch, the entry-level Porsche Boxster ($122,960).

Of course, being a premium European car, there is an extensive options list. Our car was fitted with the excellent and probably-worth-the-money M Sport differential ($2400), as well as the rudely priced M seat belts (literally just the M pattern embroidered in - $560!) and interior ambient lighting package (lovely, perhaps not worth $550).

The Z4 is only offered in five colours, three of which – including our car’s Black Sapphire – come at a cost of $2000. The red interior, surprisingly, is a no-cost option.

If you’re keeping track that brings the car you’re looking at here to $110,410. Not cheap, and it doesn’t have six-cylinders - but given its other attributes explored later in this review, the fact that it still manages to undercut an entry-level Boxster is actually reasonable.

A new (or at least, massively altered) 3.6-litre petrol engine has been developed for this T-Hybrid, which combines with two electric motors to produce a total 398kW and 610Nm. It’s only available with Porsche’s very good eight-speed Porsche Doppelkupplung (PDK) automatic, largely because the brand admits it would be… well… unpleasant to drive as a manual.

Now, there is lots of magic at work here, and I don’t want to bore you, but the Porsche setup sees a lightweight 1.9kWh battery placed basically in the middle of the front axle, and a 12-volt battery now behind the front seat. Then, a tiny e-motor lives as part of the gearbox (it’s just 55mm long) and delivers up to 150Nm at low speeds to supplement the petrol engine.

It’s joined by what Porsche calls an “electric exhaust gas turbocharger”, which essentially removes the spooling time from the turbo, delivering instant power.

The aim of the game here is excitement, not efficiency, and the launch-control-aided spring to 100km/h takes just 3.0 seconds. And it somehow feels, and sounds, faster.

The latter being important, with Porsche aware that if the new powertrain didn’t sound good, "nobody would like it”.

Welcome to the age of ridiculously powered four-cylinder turbo engines. Despite a capacity of just 2.0-litres, the engine in the Z4 30i produces a whopping 190kW/400Nm.

That’s probably enough for a car this size. I’m keen to drive the six-cylinder, but surprisingly it seems to offer diminishing returns for extra cylinders offering a 60kW/100Nm power boost for an extra $20,000. Perhaps a six-cylinder is the way to go in a BMW, and given this car’s other seriously sporty attributes, it might be the only way to make it a bit more… fun. More on that in the driving section.

All Z4s are rear-wheel drive, using an eight-speed torque converter automatic. Sorry, no option for a manual this time around.

Porsche in Australia is yet to lock in local fuel use for the Carrera GTS T-Hybrid, but international testing has it at 10.5-10.7L/100km, C02 emissions of between 239-244g/km. 

Those aren’t exactly Toyota Prius numbers. But again, that was never Porsche’s intention. The electric power on offer here is intended to improve acceleration, not fuel use.

It’s fitted with a 63-litre fuel tank, which should deliver a driving range of around 600km per tank.

It’s claimed that the Z4 will drink just 6.5 litres per 100 kilometres on the official combined cycle test, but I found that sticking my foot in occasionally resulted in a slightly more realistic sounding figure of 8.4L/100km.

That’s still a great fuel consumption number for a car like this, and perhaps one of the strongest benefits of having just four cylinders.

A discerning vehicle, the Z4 will drink nothing less than the best-quality 98RON unleaded to fill its 52-litre tank.

Porsche did just about the Porschiest thing to ever Porsche in launching the 911 Carrera GTS T-Hybrid, in that we piled into cars in Melbourne, drove the many, many hours (well, it feels that long, at least) to the Phillip Island race circuit, beat the hell out of the cars on track and on the drag strip for several hours, then trundled back out on the road and drove them back to Melbourne.

The subliminal messaging here is pretty clear. This new 911 might have a new powertrain, but it can still deliver the road-track-road experience without breaking a sweat — or, more importantly, without breaking any expensive bits.

So let’s do this in order, shall we? On the road, this new 911 is every bit as sweet as it has ever been. Comfortable, quiet enough when you want it to be, and — save some road noise from those big wheels – quiet enough to let you forget you're driving something with one of Peter Dutton’s nuclear reactors hidden beneath its svelte metal work.

Mind you, that T-Hybrid powertrain will happily remind you of its presence every time you press the accelerator in anger, the exhaust erupting into life and the 911 genuinely rocketing into the future, but stay gentle with your inputs and this hybrid 911 is a genuinely comfortable, genuinely liveable daily driver.

Its split personality appears when you rumble out onto a race track though, where you quickly discover the electrified, and electrifying, Porsche is properly, properly rapid, both in a straight line or around Phillip Island’s fast and flowing circuit.

It’s so rapid, in fact, that it feels most closely related to a performance EV, like the Taycan. Of course it is louder and more engaging, but that’s the best way I can think of to describe the instant power on offer here. There’s no ICE-like lags or lumps in the way that 398kW and 610Nm finds its way to the tyres and into the tarmac. Instead it’s just this constant, savage flow of power that never seems to let up.

Porsche says this new powertrain is about 50kg heavier, but you’d need to be plugged into the race track like its the Matrix to ever feel it, with the T-Hybrid feeling lithe, grippy and athletic, aided by near-perfect steering, the best automatic gearbox in existence, and exactly zero roll through the body. In fact, the only thing that really moves when cornering hard in this new 911 is the driver, and I genuinely got out after several laps with a sore neck from trying to stay vertical.

Downsides? Well, it’s faster in a straight line (it will be some 7.0m further down the road after 2.5sec when compared to the older GTS) and faster around corners (8.7sec faster around the Nurburgring than its predecessor), but there’s something delightfully analogue about the outgoing car, which also manages to feel more aggressive under heavy acceleration, too, owing to the little ebbs and flows of power, and after driving both back-to-back, I still can’t decide which one I like more.

A car that looks this good better live up to the promise behind the wheel, right?

For the most part, the 30i does, but it’s a victim of its own performance credentials and luxuriousness.

See, a drop-top should be fun-packed, you should feel close to the road, connected. Sadly, a combination Z4’s excellent suspension and not-so-excellent SUV-like interior separates you too much from the surface below.

An advantage, of course, is the refinement on offer. The Z4 is easily one of the quietest, most refined convertibles I’ve ever driven, but it’s a little too insulated.

I can’t help but feel like it’s all business and no pleasure. It feels a little more like I should be cruising to work on the autobahn and a little less like I should be flinging it around corners on a tight B-road.

It feels almost wrong to drive it in a T-shirt. It’s serious and doesn’t want you to mess around, it wants you to wear a suit and tie.

This grand-tourer style feel is one that will keep a lot of buyers in the premium space happy, but I’m of the opinion that BMW will have that segment well and truly covered by the new 8 Series. If the budget allows.

Regardless, the 30i’s four-cyl engine feels like any six-cylinder would have a few years ago. It’s got a surge to it in the straights that’s quite satisfying, and it responds via the exhaust with an angry tone that makes it feel a little more alive, especially with the roof down.

This feeling was all helped along by our car’s M active differential which simply won’t let the fat tyres at the rear slide unless you’ve got high-speeds and loads of tarmac to play with – for better or worse.

The Z4 also has ‘variable sport steering’ which reacts to the car’s speed and position of the wheels to adjust the input ratio. It’s good when you’re at speed, but the weight and response of the steering can make the Z4 feel bigger than it actually is at lower speeds. 

The suspension is firm, and can be a little bouncy over rough surfaces, but seems well suited to the Z4’s chassis.

Other than those notable characteristics you’ll find that the Z4 is wonderfully tuned in terms of its inputs, everything is slick and smooth, suited perfectly for long meandering drives.

Convertibles and safety don’t often fall in the same sentence, unless its one where a concerned relative is trying to convince you not to buy one.

In any case, the Z4 benefits from four airbags (dual front and dual side), as well as the expected electronic stability controls. That optional M Sport differential will have the added bonus of preventing any unexpected slip and slide at the rear.

On the active side the Z4 gets ‘Driving Assistant’ which includes forward collision warning (FCW), lane departure warning (LDW), rear cross traffic alert (RCTA), and rear collision warning. The 30i grade also gets 'active cruise control with stop & go' which allows for full auto emergency braking (AEB) with pedestrian and cyclist detection. Not on the spec sheet, but apparently present in the car I drove was some form of traffic sign recognition (TSR) and lane keep assist (LKAS).

A nice high-res reversing camera displayed on the massive touchscreen is a welcome standard addition.

Considering the meagre safety specification of most convertible cars, the Z4 30i shines with a half-way decent active safety suite. But you can forget ISOFIX child-seat anchor points. There aren't any. 

The 911 Carrera GTS is covered by a pretty underwhelming three-year, unlimited-kilometre warranty, with servicing required every 12 months or 15,000kms. We don’t have the hybrid service pricing yet, but as guide, the last 911 split the services into minor and major, and charged either $785 or $1285 for each.

If recent quotes are anything to go by BMW is set to stick by its lacklustre three-year unlimited kilometre warranty, as it says its customers simply aren’t interested in five years (or longer) when it comes to warranty coverage.

It’s a shame, as even Volkswagen has upped its warranty to five years, and Mercedes has considered a 10-year coverage plan in the past.

In terms of servicing, there are two fixed-price plans available – the suspiciously cheap ‘Basic’ plan which comes at a cost of $1373 for five years (or $274.60 per year) and the more realistic-sounding ‘Plus’ which costs $3934 over five years (or $786.80 per year).

Like every other BMW, the Z4’s computer tells you when its service time: how often it needs maintenance will depend on how often – and how hard – you drive it.