The Mercedes-AMG GT C Roadster might just be the industry's tastiest alphabet soup.

What letter is half-way between R and S? Though seemingly a trick question, the correct answer is C, as in the Mercedes-AMG GT C.

Following the launch of its AMG GT R and AMG GT S models, Mercedes' in-house hot rod division is rolling out a new trim level to round out its AMG GT lineup. It's called the AMG GT C and, as alluded to above, splits the difference between the R and the S.

So is Mercedes-AMG's new half-step worthy of consideration? Come with us as we find out.

A better GT
Mercedes-AMG will offer the new C model in both coupe and roadster forms, but our review focuses exclusively on the latter.

The AMG GT C is based on the restyled 2018 AMG GT, but there are a few key differences. The front end design carries over essentially unchanged, but the C's lower bumper conceals active air louvers borrowed from the GT R. Those louvers can close under certain circumstances, providing better airflow for less resistance. When the engine needs a little more fresh air, they can open back up in under a second.

New side sills give the C a more planted look, but the car really looks hunkered down thanks to new rear fenders lifted straight from the hard-core R model. Made from aluminum, the C's rear fenders are 57mm wider than the units used on the base GT, allowing for wider wheels and tires (305s vs. the GT's 295s) that provide better traction. Those haunches also house air vents that help improve the car's overall aero.

The interior of the C is mostly made up of GT bits, but there are a few upgraded materials and a new Race mode available via the car's control switch, but more on that later.

Changes to the AMG GT C are more than just skin deep. While displacement of the car's 4.0L twin-turbo V8 hasn't changed, its output has. That four-liter lump makes 550 horsepower and 502 lb-ft of torque under the hood of the GT C, marking a noticeable improvement over the base car's 469 horsepower and 465 lb-ft of torque ratings (the GT R is rated at 577 horsepower and 516 lb-ft of torque). Larger front brakes have been fitted to the GT C to keep that added power in check. Carbon ceramic brakes are optional.

So just how did Mercedes manage that jump in power? It started with the turbos, which are now slightly larger than before. To compensate for that added boost, engineers actually decreased the engine's compression ratio — down to 9.5:1 from the GT's 10.5:1. Other changes include a new fuel pump, machined exhaust ports and different pistons. New software was also included to ensure the massaged V8 runs at peak performance with the new components.

Power is still routed to the rear wheels via a seven-speed dual-clutch transmission, but the GT's mechanical rear differential has been replaced with an electronic unit to provide better control. But that electronic differential isn't the only notable change on the rear axle — the GT C has also been fitted with the rear wheel steering system found on the GT R, allowing the rear wheels to turn up to 1.5 degrees. At speeds lower than 62mph the rear wheels turn opposite of the fronts; cross that 62mph barrier and the rear wheels turn in unison with the front axle.

On the suspension front, the GT C has been upgraded with an AMG RIDE CONTROL system. Using adaptive dampers, the RIDE CONTROL system can automatically change the car's ride and handling characteristics based on speed and road conditions. You can also manually change the settings via a knob on the center console.

Taking it all in
Naturally your tastes may vary, but we prefer the looks of the new GT C to the standard GT. The overall design of the C just looks a little more cohesive to our eyes — the wider rear end seems to fit better with the car's redesigned nose, which has been tweaked to give the car a lower and wider stance. The differences are admittedly subtle, but they add up to a better looking GT in our eyes.

Drive time
It's pretty easy these days to stack a spec sheet with an impressive list of numbers. But oftentimes those figures don't paint an accurate picture of what the car's actually like to drive. In the case of the AMG GT C Roadster, it more than lives up to what Mercedes promises on paper.

The first thing you notice when driving the AMG GT C is just how nimble it feels. Steering is extremely sharp and direct with good feel, no doubt aided by the C's four-wheel steering system. The GT C darts from corner to corner, emulating what it must feel like to ride on the back of a flea.

Of course good handling is the result of more than just a good steering system. In the case of the AMG GT C, that starts with an exceedingly stiff chassis that has been reinforced for Roadster duties. Not even the roughest of road surfaces produced any noticeable vibrations or shimmies in the GT C's structure during our day-long drive. And with that strong foundation in place, the GT C's AMG RIDE CONTROL sports suspension with Adaptive Damping System is free to work its magic.

The ride quality of that AMG RIDE CONTROL suspension is surprisingly supple no matter the setting. We're not talking S-Class Cabriolet levels of comfort, but the GT C certainly provided a better ride than we were expecting from a dedicated sports car, especially one that is largely based on the rough-riding SLS. But despite its relatively comfortable ride, the AMG GT C corners with virtually no body lean to speak of.

Although we're admittedly still mourning the loss of AMG's sensational 6.2L naturally-aspirated V8, the division's new twin-turbocharged V8 is one hell of a replacement. That mill makes a sweet-sounding 550 horsepower under the hood of the GT C, which is good enough for a claimed 0-60 run of just 3.7 seconds. Moreover, it's a snap to reproduce those kind of acceleration runs thanks to a dead-simple launch control system — with the performance knob switched to either Sport, Sport+ or Race, simply stab the gas and brake at the same time and then release the brake pedal when you're ready to take off.

And take off the GT C does. Keep the skinny pedal buried and you'll be in the triple digits before you can say, "Please don't arrest me, officer." And if you've got the guts and enough empty road, AMG says the GT C will keep on accelerating all the way up to 196mph. We recommend the GT C's optional carbon ceramic brakes to keep that kind of speed in check.

But even with those super car credentials, it's still easy to use the AMG GT C as just an ordinary car, which was one of Mercedes' main goals from the onset.

The seven-speed dual-clutch unit in the GT C has some of the inherent clumsiness of any dual-clutch gearbox at low speeds, but it's not annoying to the point that it detracts from the driving experience. It's also quite smooth once you get rolling. However, the entire drivetrain feels a little lazy in the Comfort setting so we'd recommend avoiding it altogether. Sport mode is noticeably more responsive than Comfort mode, but we found the sweet spot to be Sport+ with its ability to hold gears longer and its automatic disabling of the GT's auto stop-start system. For all out performance, Race mode cranks up all of the GT C's components — from throttle and gearbox to suspension and exhaust — all the way to 11. Race mode makes for a good companion on an empty mountain road, but just be aware that it also tells the electronic nannies to back off. Get it wrong and you have to own it.

Sports seats are usually just another way of saying "sore lower back," but the optional AMG units in our test car proved to be surprisingly comfortable over our 300+ mile journey. Padding is firm, but the AMG thrones provided excellent support in all the right places. We also enjoyed the optional AirScarf neck warmers when the weather turned cool.

The cabin of the AMG GT C is a little cozy thanks to a high belt line, but hip and leg room should be fine for those six-foot or a little taller. The GT C Roadster can, however, feel a claustrophobic with the roof up. Luckily its cloth roof can be lowered in about 11 seconds.

Storage space is at a premium inside the GT C's cockpit, but the trunk is actually rather generous; you should be able to fit luggage for two or a golf bag without issue. Our only real ergonomic gripe with the AMG GT C Roadster is a center armrest that is located too far back to easily use. As a result of its placement, our elbow hit the suspension button where the armrest should be located on a couple of occasions.

Pricing has not been announced for the 2018 Mercedes-AMG GT C Roadster, but expect a price tag somewhere in the neighborhood of $155,000, placing it squarely between the Porsche 911 4S Cabriolet and the 911 Turbo Cabriolet.

Leftlane's bottom line
Don't let the stereotype of the AMG badge fool you; the GT C isn't just some shouty car that's only good at going fast in a straight line. It's far more talented than that, with the ability to corner and brake with the best in the world.

The AMG GT C Roadster is arguably Mercedes' first true sports car since the original Gullwing. But one thing you can't dispute is that buyers looking for an everyday super car now have a worthy alternative to the Porsche 911.

Photos courtesy of Mercedes.