BMW M4 Convertible vs Jaguar F-Type V6 S vs Porsche Boxster GTS

Once upon a time, the only real sports cars were convertibles.

Sure, there were sporty cars with roofs, but if you wanted a proper driving experience, you needed the wind in your hair and the sun on your face. The flies in your eyes and grit in your teeth weren’t mentioned so much, but let’s not spoil the romance. Cruising along a winding road in an Austin-Healey 3000 or Alfa Giulietta Spider – driving nirvana.

At some point, however, possibly around the muscle car era of the late 60s or early 70s, it all went awry. Open-top cars became wobble-bodied pose machines, built for the Cote d’Azur rather than the Col de Turini; more Sunset Boulevard than Spa-Francorchamps. They remain hot property, though, so with another Aussie summer upon us we felt it was time to discover what today’s drop-tops bring to the table.

The catalyst for assembling this trio of tan-assisters is the release of the F32 M4 Convertible. Unsurprisingly, it shares the M4’s 317kW and 550Nm 3.0-litre twin-turbo six, seven-speed dual-clutch gearbox, heavily revised suspension and clever electronic differential.

Losing the roof adds $12,000 to the price ($178,430), while the complex folding hardtop and requisite body strengthening add a hefty 253kg to the kerb weight. The F32 is, however, 60kg lighter than its predecessor and, in dual-clutch form, cheaper too.

Its closest challenger, on paper at least, is Jaguar’s F-Type V6 S. Priced at $170,575, the V6 S also packs a 3.0-litre force-fed six-cylinder, albeit in vee configuration and boosted by a supercharger rather than a pair of turbos, delivering 280kW and 460Nm. This is our first proper exposure to a six-pot F-Type – can it match the thrills offered by its V8-engined siblings?

Our final contender is the Porsche Boxster. It’s been around a while, but appears here in fresh-off-the-boat GTS guise. The GTS badge has developed a reputation for signifying the sweet spot in Porsche’s various model ranges, which is perhaps unsurprising as it essentially cherry-picks the choice options such as Porsche Adaptive Suspension Management (PASM), Sport Chrono, sports exhaust and 20-inch Carrera S wheels.

The GTS treatment also brings a slight lift in output to 243kW and 370Nm. Even fitted with the seven-speed PDK ’box, though, it’s easily our cheapest contender at $151,790.

The packaging advantages offered by its mid-engined layout also make it by far the smallest car here. Each successive Boxster has been more aggressive than the last, but it’s still more feminine than its brawny, traditional front-engine, rear-drive rivals. It’s a good-looking thing, even if the black highlights of the GTS make it look a bit like it’s going through a teenage ‘emo’ phase.

At the other end of the scale is the M4. With a wheelbase 337mm longer than the Boxster it looks like a stretch limousine in comparison. But that’s the price you pay for providing decent accommodation for four, rather than two.

It certainly doesn’t lack aggression; M cars of old were subtle to the point of anonymity (which isn’t without its virtues) but there’s no doubting the M4’s intent. Following it in the Boxster, its narrow glasshouse and Kardashian hips give the impression that it’s swallowed a lesser 4-Series whole.

When it comes to the catwalk, though, appropriately it’s the Jaguar that steals the show. Wherever it pulls up passers-by point and produce camera phones. You could argue that it’s not quite as good-looking as its hardtop twin, but that’s like debating who’s the better looker out of Miranda Kerr and Mila Kunis.

Its case is further enhanced by green and red flecks in the black paint that sparkle in direct sunlight and those carbon-bladed 20s, which look so good $6800 suddenly doesn’t seem so steep.

On the move the Jaguar continues to entertain. You have to wonder why Jaguar offers the option to quieten the exhaust – surely no owner would ever bother? It rasps its way to the 6500rpm redline and does its best Call of Duty shootout impression on the over-run. The blown V6 offers impressive throttle response and a great spread of linear power – why aren’t there more supercharged cars? – though it does feel a little soft at the top end.

At the strip it reels off 4.98sec to 100km/h and a 13.16sec quarter mile at 175.79km/h. It’s a breeze to launch: load it briefly against the brake and floor the throttle. There’s next to no wheelspin and the quick-shifting, close-ratio eight-speed ZF auto makes the most of the available power, while also proving that even the best dual-clutch gearboxes are yet to match the low-speed smoothness of a good automatic.

The Jaguar does have launch control, but any attempt to use it resulted in an electronic tantrum, and it’s unlikely it would’ve gone much faster anyway.

What could have gone faster is the Boxster. Its 5.11sec 0-100km/h and 13.29sec quarter mile times (at 173.77km/h) were well down on the 4.49sec and 12.66sec recorded in the (almost) mechanically identical Cayman GTS at PCOTY last year.

Blame the surface. On Heathcote’s slippery start line, launch control simply blazed the rear tyres and any other technique was still slower than letting the electronics do it. In one way the numbers are representative, though, as the Boxster feels a little slower than the Jag.

But who cares about numbers? The 3.4-litre naturally-aspirated flat-six nestled deep inside the Boxster is about as good as engines get. With not much in the way of torque, it’s never going to blow you away with sheer speed, but it revs to the heavens (7800rpm) and the noise, oh, the noise. Hit the exhaust button, find a tunnel and you’re guaranteed to dissolve in a fit of hysterics – it sounds like an old-school Le Mans racer.

Allowing emissions regulations to kill this engine in favour of a 2.0-litre turbo four should be a crime against the Geneva Conventions, particularly since this ‘high-polluting’ atmo engine averaged a parsimonious 10.2L/100km, compared to 12.0L/100km for the Jaguar and 12.1L/100km for the BMW. Forced induction might shine on the highly controlled (and highly misleading) official consumption test, but in the real world the evidence doesn’t match the manufacturer’s claims.

If there’s one blot on the Boxster’s copybook, it’s the gearing. Second gear stretches to a ridiculous 137km/h, which, if you’re going to respect the law, limits the Boxster to first and second gear on any road in Australia. And that’s a shame, because the ’box is sublime, with unparalleled smoothness (for a dual-clutch), almost instant changes and a sixth sense about the appropriate gear to use, if left to its own devices.

It certainly shows up the BMW’s DCT. Once on the move it’s superbly responsive with lightning-quick shifts, but the engineered-in thump during full-throttle upchanges is irritating (and can break traction on slippery surfaces) and its low-speed behaviour is often clumsy. Simply performing a smooth three-point turn can take an age.

When it comes to speed, however, the M4 is in a class of its own. Despite being the biggest and heaviest (1750kg) car here, its greater power and excellent launch control system delivered 0-100km/h in 4.46sec and a 12.61sec quarter mile at 184.74km/h. M4 first, daylight second. The figures are no surprise from behind the wheel, as the BMW feels appreciably the fastest of the trio.

Whereas occasionally the old M3’s atmo V8 struggled with the extra heft of the convertible bodyshell, like it was attempting to give a large friend a piggyback up a steep hill, the M4’s torque-rich twin-turbo six shrugs off the added weight with the ease of a front-runner in the Wife Carrying World Championships (actually a thing!).

Sadly, one area the new engine is no match for its predecessor is noise, though it is at its best in the Convertible. While it never approaches the heaven-sent soundtrack of the old bent-eight, with the roof down you are privy to all sorts of growls, snorts and bangs that remain unheard in the hardtop. It turns out the new M4 sounds pretty good. You just usually can’t hear it.

For some, the added pace will be ample compensation because you arrive at corners at a fearsome rate. Thankfully, while they lack initial bite, the brakes are up to the task, though it’s difficult to overestimate corner entry speed in an M4 due to its incredible amount of front-end grip – unless you take your brain out, understeer doesn’t really exist on the road.

In the dry, traction is incredibly strong, though when it does run out you have to act quickly to catch the ensuing slide. Back-to-back with the Coupe you’d no doubt feel the extra weight of the drop-top, but in isolation it’s still more than capable of tearing any given road apart. Keep that roof up when you’re having a punt, though, as there’s an alarming degree of body wobble over bumps in al fresco mode.

Lacking the BMW’s hardtop, the Jaguar suffers from a slight lack of rigidity roof up or down, though it’s nothing like as pronounced as the M4. It’s initially difficult to get into a rhythm with the F-Type, its short wheelbase and quick off-centre steering response making it feel nervous, but soon you’re digging into its huge reserves of grip and revelling in its agility.

Unlike the Germans, you’re unable to separate chassis and engine settings, so the Jag is either ‘Dynamic’ or not. Being able to select Dynamic for the powertrain while retaining the softer chassis setup would be beneficial, as the F-Type can skip over bumps in its stiffer setting.

In fact, the ride is pretty firm regardless. The front end also doesn’t always provide the feedback you’d like, either, and the mechanical limited-slip diff is far too loose, the inside rear wheel easily spinning up out of corners. It feels at its best – which admittedly is very good – at about eight-tenths, but there’s no way it can match the M4’s pace.

To be fair to the Jaguar, it’s unlikely the Porsche could either, but just like at the drag strip, you’re unlikely to care. The Boxster GTS is an incredibly honed machine, one that’s very difficult to pick holes in – the brake pedal is slightly too sensitive, and on the road it’s occasionally hard to feel how much grip is left in the front-end, but that’s about it.

The structure feels every bit as stiff as the Cayman, the ride is sublime – by far the best here – the brakes are brilliant, the list goes on. More than its component parts, though, it’s the way the Porsche gets better and better the harder you push, rather than coming apart at the seams, that sets it apart.

It works on an everyday level, too. There’s a fair amount of road noise on the highway, but around town the excellent ride and PDK gearbox make it a cinch to drive. There’s plenty of storage space front and rear, but it’s a shame Porsche sees fit to charge extra for both parking assist ($2850) and metallic paint ($1850) on what is a $150,000 car. Along with a few other options (see specs panel) it lifts the as-tested price to $167,150.

Porsche isn’t alone in this game, though. Our test F-Type V6 S is $184,800, with Jaguar also asking extra for basics such as metallic paint ($2810) and parking assist ($1725), though the latter is now standard on the (more expensive) MY16 F-Type. And then there’s its practicality, or lack of it.

Forgo a space-saver spare and the boot will accommodate a couple of squishy bags, but with a spare in place there is virtually zero luggage space, meaning you either travel alone and use the passenger space for luggage or limit your F-Type experience to day trips.

If you want to carry more than one passenger, then there’s only one car here for you. The M4 Convertible’s ability to carry four people and luggage sets it apart from its two-seat rivals, and combined with its incredible pace and classy looks, it’s a very appealing proposition to a certain sort of buyer. But that buyer isn’t us.

While far better to drive than most will give it credit for, it just goes against everything the M Division stands for. What’s the point of engineers slaving away for months saving every gram of weight possible only to add 250kg back on? That the BMW M4 was most enjoyable cruising around town kind of says it all.

The Jaguar does an excellent job of being the quintessential British roadster. It’s dripping with character inside and out and looks and sounds amazing. Unfortunately, while a likeable car, in pure driving terms the jiggly ride gets irritating and the handling isn’t sharp enough to compensate.

The V6 S is probably our favourite F-Type convertible, though. Some will miss the eye-widening acceleration of the V8, but the chassis feels perfectly matched to the lesser urge of the blown V6.

In terms of ability, however, there is a clear winner. The Boxster GTS comes incredibly close to receiving the full five stars, simply because there are so few ways in which to improve it. It’s the most comfortable car here, yet also the sharpest and most rewarding to drive.

Personally, I’d choose it over the Cayman, simply because having no roof doesn’t seem to penalise it in any way yet gives even better access to that incredible engine note.

You might no longer need to have a convertible to have a real sports car, but if you want a proper driving experience, you need a Boxster GTS.