2018 Mercedes-AMG GT C Roadster
When the Mercedes-AMG GT emerged back in 2014 as the lighter, nimbler, and cheaper successor to the SLS AMG, not only were the 456-hp base and 503-hp S variants arguably among the company’s most focused and well-balanced performance cars since the original 300SL, the coupes finally gave Mercedes something it had always lacked: legitimate competition for Porsche’s iconic 911 Carrera.
Key to the 911 Carrera’s lasting popularity is the sheer variety of models offered, including the most basic stick-shift coupe; the opulent, 580-hp Turbo S cabriolet; and the hypervisceral, track-oriented GT3. With each Porsche feeling as special as—or more special than—the last, Mercedes knew it eventually would have to cook up more flavors of the GT to give the 911 a run for its money.
Three years on, as the AMG coupes undergo mid-cycle enhancements and slight horsepower bumps to 469 and 515 horsepower, reinforcements have finally arrived. Four additional models triple the GT lineup for 2018: the long-awaited roadster version of the GT; new GT C coupe and roadster models with 550 horses and comprehensive AMG performance enhancements; and the wicked, track-focused 577-hp GT R, a monster coupe that topped our 2017 Lightning Lap competition. The six-model lineup definitely will help the GT compete with the 911, but does each feel special in and of itself? We’re on a mission to find out, having just tested a new GT C roadster—which seems purpose-built to go head to head with Porsche’s sporting 911 GTS cabriolet. As it turns out, however close it may be to matching or surpassing its Porsche nemesis on paper, the AMG offers delights all its own.
A Devil with a Blue Dress
The GT C roadster is gorgeously curvaceous, from its convex Panamericana grille to its tapered rear end, and looks as beautiful as its coupe counterpart despite lacking the domelike roof. As do the 911 GTS and the Chevrolet Corvette Z06 in comparison with their lesser siblings, the GT C features a wider rear end than the GT/GT S—some 2.7 inches wider in this case—to accommodate a greater rear track and fatter rear tires (size 305/30ZR-20, up from 295/35ZR-19). Standard rear-wheel steering offers up to 1.5 degrees of toe movement. Flared side sills and active front aero splitters are both highlighted rather garishly in chrome unless one springs for the $750 Exterior Night package that renders most brightwork in gloss black. This car’s black softtop might have looked more interesting against its $720 Brilliant Blue paint in the optional brown, but even spec’d exactly like our test car the GT C roadster is fantastic to behold.
We weren’t alone in our admiration, as we found while driving all around Los Angeles, where six-figure convertibles are as common as palm trees and dubious “service animals.” We couldn’t have gotten more attention if we had Playboy bunnies shooting fireworks off the trunk. Tourists, tour guides, street merchants, and even LAPD officers craned their necks and gaped. Dropping the top would drop jaws, putting the GT C’s remarkable lowness and its formidable 79.0-inch width—just 0.4 inch narrower than the 2018 Rolls-Royce Phantom—on full display.
Those who didn’t see the car could certainly hear the deep rumbling exhaust note delivered by the GT C’s standard AMG Performance exhaust system. With the car’s driving mode set to S+, a throttle blip followed by a delicious whip-crack pop-pop-pop on overrun was always good for a thumbs-up or two.
Target: 911 GTS Cabriolet
At the track, the GT C roadster turned in performance numbers close to those of its bogey, the 911 GTS cabriolet. Zero to 60 mph requires 3.3 seconds in the AMG—0.3 longer than the Porsche—but by 100 mph the two cars are tied at 7.3 seconds. By 130 mph, the GT C is a second ahead of the Porsche, a gap that grows to two seconds by 150 mph. Both cars clocked 4.0 seconds in our 5-to-60-mph rolling-start test. Each could claim some passing-lane bragging rights, with the GT C sprinting from 30 to 50 mph in 2.2 seconds and from 50 to 70 in 2.7, while the Porsche did both deeds in 2.5.
We actually expected the new GT C to be quicker, considering that we hustled a 503-hp 2016 GT S coupe to 60 in 3.0 seconds flat during a 2015 comparison test. This car, however, reached most milestone speeds between 0.1 and 0.4 second behind the less powerful GT S despite its additional horsepower, revised gearing, and even more rear-biased weight distribution. The difference could be attributable to fuel quality—the comparo was done in Europe—and the GT C ragtop’s additional 127 pounds.
Stomp on the gas in a GT C and such discrepancies seem academic. In practice, catapulting to 60 mph in 3.3 seconds in this AMG is a neck-snapping, hold-on-with-both-hands, giggle-inducing riot, especially with the top down so that the sublime, unfiltered soundtrack washes over the occupants. Torque is omnipresent, with all 502 lb-ft available from 1900 rpm and served with almost zero lag in Sport or Sport+ modes.
The GT C roadster’s formidable 1.04 g’s of lateral grip edges out the lighter 911 GTS cabrio’s by 0.01 g, with quick off-center steering response and pan-flat body control. At 151 feet from 70 mph to zero, however, the car’s braking performance was a tad disappointing, some 10 feet longer than the GT S coupe’s despite this car’s $8950 carbon-ceramic brake discs. Even so, brake-pedal feel was pretty much perfect.
911-Fast Is Not 911-Like
If the GT C’s mandate is to match the 911 GTS move for move, we’d say mission accomplished. But the two cars aren’t really similar in character. As we noted in our first drive of the GT C coupe, AMG may be aping Porsche’s 911 model structure but is doing so with “a completely different sort of car.” And this, we think, will help the GT C succeed. With its long wheelbase, prominent hood, and set-back cabin, the big Mercedes doesn’t place the driver right in the action the way the Porsche does. This means the driving experience is rather more like an Aston Martin DB11’s—spectacularly fast and engaging when driven at 11/10ths but gran turismo chill when just cruising around, with adaptive dampers keeping the ride heroically smooth in all but the Sport+ setting.
There’s a particularly high sense of occasion inside the GT C’s richly ornamented cabin. The saddle-colored nappa leather is standard, while the matte-finished carbon-fiber trim came as part of an optional package that added a reasonable $3150 to the roadster’s $158,995 base price. Other upgrades included a $1500 carbon-fiber engine cover, a $4500 Burmester audio system, and the $2250 Distronic Plus cruise-control setup. This GT C roadster’s as-tested price was $180,065—that’s Audi R8 V10 Spyder/Porsche 911 Turbo cabriolet money and could come across as rather ambitious. Then again, the AMG GT is much cheaper (and quicker) than the preceding SLS AMG as well as that car’s predecessor, the SLR McLaren. And when it comes to sheer curb appeal, nothing short of a current McLaren gets this much positive attention.
While very little daylight exists between the objective performance levels of the AMG GT C and 911 GTS convertibles, the two cars feel as if they were developed on different planets. The GT C may be as quick, but it offers looks, sensations, and sounds all its own. We think it’s okay to like them both.
Specifications >
VEHICLE TYPE: front-engine, rear-wheel-drive, 2-passenger, 2-door convertible
PRICE AS TESTED: $180,065 (base price: $158,995)
ENGINE TYPE: twin-turbocharged and intercooled DOHC 32-valve V-8, aluminum block and heads, direct fuel injection
Displacement: 243 cu in, 3982 cc
Power: 550 hp @ 5750 rpm
Torque: 502 lb-ft @ 1900 rpm
TRANSMISSION: 7-speed dual-clutch automatic with manual shifting mode
DIMENSIONS:
Wheelbase: 103.5 in
Length: 179.2 in
Width: 79.0 in Height: 49.6 in
Curb weight: 3804 lb
C/D TEST RESULTS:
Zero to 60 mph: 3.3 sec
Zero to 100 mph: 7.3 sec
Zero to 130 mph: 12.1 sec
Zero to 150 mph: 17.0 sec
Rolling start, 5–60 mph: 4.0 sec
Top gear, 30–50 mph: 2.2 sec
Top gear, 50–70 mph: 2.7 sec
Standing ¼-mile: 11.4 sec @ 126 mph
Top speed (drag limited, mfr's claim): 196 mph
Braking, 70–0 mph: 151 ft
Roadholding, 300-ft-dia skidpad: 1.04 g
C/D FUEL ECONOMY:
Observed: 14 mpg
75-mph highway driving: 20 mpg
Highway range: 340 miles
EPA FUEL ECONOMY:
Combined/city/highway: 17/15/20 mpg
