Audi S5 vs BMW Z4

What's the difference?

The S4 and S5 range continues to represent a great formula for performance you can live with every day. They're arguably the sweetest balance Audi produces, actually. All come fantastically equipped, with cabins that feel truly special, and we’re lucky they can be had in a choice of five bodystyles.  

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.

The S4 sedan and Avant have scored the bulk of design updates, with all new and recontoured side panels including the sedan’s C-pillar matching what was applied to the A4 earlier this year. 

This is paired with new front and rear facias and lighting for a subtle but extensive rework of the fifth-generation S4’s conservative look. 

The S5 Sportback, Coupe and Cabriolet get S5-specific new lighting and facias, but no sheetmetal changes. As before, the Coupe and Cabriolet ride on a 60mm shorter wheelbase than the Sportback, sedan and Avant.

The S5s also get Matrix LED headlights as standard which do a neat animated sequence when you unlock the car. 

Other visual hallmarks include new S4-specific 19-inch wheels, with S5 stepping up to its own unique 20-inch wheel. The six-piston front brake calipers are appropriately painted red, and there’s S-specific adaptive dampers under there too. All variants aside from the Cabriolet get a lip spoiler on the rear.

On the inside, there’s a new centre console and bigger 10.1-inch multimedia screen, while the Audi Virtual Cockpit driver instrument display now offers a hockey stick-style rev counter in additional to traditional dial layouts.

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.

The biggest practicality change among the five S4 and S5 variants is their upgrade to the latest version of Audi’s MMI multimedia system, which steps up to a 10.1-inch touchscreen and drops the scroll wheel from the centre console.

It also boasts ten times the computing power of the version it replaces and uses this and an on-board sim card to access Google Earth maps for navigation and Audi Connect Plus that offers driver information such as fuel prices and parking information as well as point of interest search and weather information, plus the ability to make emergency calls and seek roadside assistance.

There’s also a wireless phone charger, but using Apple CarPlay will still require a cord as per Android Auto.

I only drove the S4 Avant and S5 Sportback at their media launch, which are clearly the most practical of the five, but from our experience with the previous versions, each looks after its occupants well in terms of space and storage. Back seat accommodation is clearly not a priority in the Coupe and Cabriolet, but there’s three other variants if that’s what you’re looking for. 

The Cabriolet can open its automatic folding soft top within 15 seconds, at speeds of up to 50 km/h.

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.

Audi has taken an ‘if it ain’t broke’ approach with the mechanicals, with all S4 and S5 models unchanged with this update. So the centrepiece continues to be the single-turbocharged 3.0-litre V6 that produces 260kW and 500Nm, with the latter available from a broad 1370-4500rpm.

The rest of the drivetrain is also unchanged, with the venerable but excellent ZF eight-speed torque converter auto paired with the Quattro all-wheel drive system that can send up to 85 per cent of drive to the rear wheels. 

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.

Official combined fuel figures range from 8.6L1/00km for the S4 sedan to 8.8L/100km for the Avant, Coupe and Sportback, while the heavier Cabriolet steps up to 9.1L/100km. 

All are pretty good considering their performance potential and the size of these cars, plus the fact that they only require 95 RON Premium Unleaded fuel.

All have a 58-litre fuel tank, which should enable a range of at least 637km between fills based on the Cabriolet’s figure.

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.

The S4 and S5 range were already an excellent balance between everyday comfort and a genuine sporting edge, and nothing has changed with this update.

I spent time behind the wheel of the S4 Avant and S5 Sportback at their media launch, and both managed to deliver the proper Audi luxury experience over some pretty rough rural roads, while always feeling a bit more sporting than a regular A4 or A5. That’s with the Drive Select left in the default mode, but you can shift that sporting personality up a few notches (while scaling back the comfort), by selecting Dynamic mode. 

My preferred means of adjusting their personality is by simply tugging the transmission selector back to activate S mode, which livens up the engine and transmission without stiffening up the suspension. 

Across the five S4 and S5 bodystyles, there is some variance in performance potential, with the S4 sedan and S5 Coupe topping the performance chart with 0-100km/h boasts of 4.7s, with the S5 Sportback trailing them by 0.1s, the S4 Avant by a further 0.1s and the Cabriolet managing a still-fast 5.1s claim.

Another area I consider the S4 and S5s to get just right is their exhaust note. It is adaptive, but there’s nothing synthetic about it, and the generally muted and distinctly V6 burble is always there to remind you that you’re aboard a proper performance model, but not in such a way that it will annoy you, or your neighbours. Polite performance, if you will.

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. 

Audi continues to offer a three year, unlimited kilometre warranty, which is in line with BMW but lags behind the five years offered by Mercedes-Benz these days. This also contrasts with the five year norm among mainstream brands, which is punctuated by the seven year warranties of Kia and SsangYong.  

Service intervals are a convenient 12 months/15,000km though, and the same five year ‘Audi Genuine Care Service Plan’ offers capped price servicing for the same $2950 total over five years applies to all S4 and S5 variants. This is only marginally more than the plans offered for regular petrol A4 and A5 variants, so you’re not being stung for the thoroughbred versions.

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.