Mercedes-Benz has expanded its family of AMG GT Roadster models with the addition of a third, mid-level trim called the AMG GT S, bringing the car's droptop range more closely in line with that of its coupe sibling.

The GT S Roadster follows last year's introduction of the GT and GT C Roadsters, introduced as 2018 models.

As with the GT Coupe, the GT S Roadster slots in between GT and GT C models with a twin-turbo V8 tuned for 515 hp and 494 lb-ft of torque; the GT and GT C use the same engine with their own trim-specific performance levels.

With that engine feeding the rear wheels through a seven-speed dual-clutch transmission, Benz says the GT S Roadster is capable of a 3.8-second sprint to 100 km/h on its way to a top speed of 308 km/h.

As with the GT S Coupe, the S Roadster gains a few other high-performance bits not shared with the base GT. Those include larger front brakes and a five-mode dynamic select drive mode system that adjusts powertrain response as well as the car's adaptive damping suspension and variable exhaust flaps.

There's also an electronically controlled limited slip differential that Mercedes says makes the car more predictable to drive at its handling limits.

Options include staggered 19-inch front and 20-inch rear wheels (the standard setup puts 19s at all four corners) and a dynamic plus package that brings a performance microfibre-trimmed steering wheel; dynamic engine and transmission mounts; upgraded gauge cluster; and specific steering, engine and suspension tunings.

Mercedes-Benz says the AMG GT S Roadster is available to order now through the company's Canadian dealers, with deliveries set to begin in the fall. Pricing is slated to be announced this summer.