Mercedes-AMG GT Roadster review

AMG might be famous for shoehorning big engines into luxurious saloons and SUVs, thereby endowing them with supercar-bothering acceleration, but let’s not forget they also build two-seat sports cars, such as the Mercedes-AMG GT Roadster.

Like the AMG GT Coupe, which you can read about by clicking the link, the GT Roadster comes with a stonkingly potent, twin-turbocharged 4.0-litre V8 engine under that long, long bonnet. And, while it's the only engine available, it's available with a choice of power outputs to suit a wider spectrum of tastes and budgets.

Regardless of power output, the V8 drives the rear wheels only, though a seven-speed automatic gearbox. All variants get an electronically controlled limited-slip differential, to help boost traction off the line and out of corners, which means that even the least powerful model, the GT C Roadster, can rattle off the 0-62mph sprint in a mere 3.7sec. Oh yes, and flat out it’ll reach 196mph.

However impressive those numbers are, the GT Roadster has a stern fight on its hands. Not only does it need to compete with the ever-popular Porsche 911 Cabriolet, there’s also the Audi R8 Spyder to think about. Meanwhile, the pricier GT R version is treading on the toes of bespoke supercars, like the McLaren 570S Spider.

To find out how it performs on the road and what it’s like to live with, keep reading over the next few pages. And, whichever car you decide on, do take a look at our New Car Buying pages for big savings on a huge variety of makes and models.

Both variants of the GT Roadster come with a switchable performance exhaust as standard. This guarantees a hearty roar when accelerating and, in the more extreme driving modes, plenty of pops and bangs when flicking down the gears. It's more enlivening than the 570S Spider's V8, although the Porsche 911 Cabriolet's flat six and the Audi R8 Spyder's V10 sound just as purposeful and less exaggerated. 

With 569bhp, the GT C feels ridiculously quick in a straight line. Believe it or not, though, both the Audi R8 Spyder Performance and McLaren 570S Spider still manage to be half a second quicker than its 3.7sec 0-62mph time. So, ardent speed-freaks might consider jumping up to the even more powerful 577bhp GT R for a bigger buzz, but at 3.6sec from 0-62mph, even that's not as quick as the quickest competition.

In the corners, the GT Roadster isn't as light or as agile as the best open-top supercars. The standard four-wheel steering is designed to aid low-speed manoeuvrability and high-speed stability, but it just makes the car feel unnatural and digital as you turn in to bends.

Then there's the GT's weight. Not only does it feel girthy on narrow country lanes, it's also pretty hefty on a set of scales. And the general impression is of a car that's more about show than serious driving; and this slightly cartoonish character runs to the more focused GT R, too. If you want a sports convertible that delivers pure driving pleasure, our advice would be to buy a 911 or 570S instead.

Is it comfortable? Well, potholes and abrupt surface changes cause the suspension to thud a bit, and a BMW M8 Convertible would isolate you better, but the GT rides most bumps quite well if you leave the standard adaptive dampers in their softest setting. It helps that there’s little sign of the body flex that so often afflicts convertibles.

Appealing though the engine's noise is when you’re having a blast, on the occasions when you desire settling back into a relaxed cruise, it's still there. And on coarse motorway surfaces GT Roadster's beset with plenty of tyre roar; but then again, so is a 911.

With the roof down at 70mph you’re well protected from wind buffeting. The roof is electrically operated, takes 11sec to raise or lower, and can be operated while driving at speeds of up to 30mph, which is useful if there’s a sudden downpour. You also get Mercedes’ Airscarf system, which blows a steady stream of warm air onto the back of your neck, making top-down winter driving more viable.

The interior of the GT Roadster looks almost as dramatic as the outside, thanks to its bulbous centre console that fences off the driver from the passenger. The material quality is sadly lacking, though.

Some of the plastic panels are lightweight – the stability control panel on the GT R is flimsier than an OJ Simpson defence plea – and the faux-metal trims on the centre console, which again are plastic, are seriously low-rent for such a high-value car. Oh yes, and you even get plastic 'leather' and fake suede seat trim on the GT C. McLaren, Porsche and Audi all do it much, much better.

On the centre console, you’ll find a myriad of buttons and switches to change the character of the car. Among other things, you can adjust the responsiveness of the accelerator, the speed of the gearshifts and the loudness of the exhaust.

Fortunately, changing these settings isn't as complicated as it looks at first glance, but the oddly positioned gear selector – it's closer to your elbow than your hand – makes swapping from park to drive or reverse an act of contortion. 

The infotainment system is standard Mercedes fare. That means most major functions are easy enough to use, and it's a more up-to-date Mercedes interface than the one Aston Martin borrows for its DB11 Volante, thanks in part to a larger, clearer 10.3in screen. That said, the touchpad controller isn't as intuitive as the rotary dial you get in a BMW M8 Convertible or Audi R8 Spyder, and the software isn't as slick. Add the Plus Package and you'll get an upgraded Burmester stereo with 10 speakers and 640 watts.

The standard digital dials, arranged on a 12.3in screen, are easy to read and can be set-up in various styles. There’s also lots of seat and steering wheel adjustment to help drivers of different sizes get comfortable, and the seats themselves are supportive – especially the AMG bucket seats that are available with the GT R.

With the roof up, looking through the small rear window, visibility isn’t great, so when reversing you'll still be glad of the standard rear parking sensors and rear-view camera. That long bonnet – the end of which you can’t really see – means you’ll be relying on the standard front parking sensors, as well. The LED headlights are usefully intense, though.

Whereas the Porsche 911 Cabriolet provides a pair of small, but useful, rear seats, the GT Roadster is a strict two-seater like the McLaren 570S Spider and Audi R8 Spyder. However, a pair of six-footers will have plenty of head and leg room, although, due to its relative lack of in-car storage, there's not much room for your odds and sods.

And there's not a lot more room in the boot. Its 165-litre capacity is close to half that provided by the GT Coupe. That's enough for a couple of weekend bags, but not a lot else. That's another good thing about the 911's rear seats; they can double up as extra luggage space when required. Meanwhile, the BMW M8 Convertible simply offers a bigger boot, full stop.

Even the cheapest GT C is one heck of a big chunk of change – far more expensive than the entry-level Porsche 911 Cabriolet or BMW M8 Convertible. The pricier GT R Roadster is big step up in price again, costing more than seemingly highly exclusive models, such as the McLaren 570S Spider or Aston Martin DB11 Volante. 

Fuel, tax, insurance and tyre bills are also going to be steep, but the same is true of its rivals. As the saying goes: if you can afford to buy it, you can probably afford to run it.

The GT C Roadster comes reasonably equipped, with 19in alloy wheels at the front and 20in wheels at the rear, dual-zone climate control, power-fold door mirrors, red brake calipers, an automatically dimming rear-view mirror and keyless entry. There are plenty of pricey performance options, such as track-focused carbon-ceramic brakes, and styling upgrades, should you wish to stand out from the crowd.

In terms of which GT Roadster you should buy, we reckon stick to the GT C. As we've described, the GT in any guise isn't the best sports car to drive, so if it takes your fancy, enjoy its looks and noise for the least outlay.

Safety equipment includes automatic emergency braking, traffic sign recognition and driver attention alert, but the GT hasn't been certified by Euro NCAP. 

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