Ever since the 300SL was launched in the 1950s, Mercedes-Benz’s flagship roadster has been an understated icon of style.

2017 Mercedes-AMG SL65
2017 Mercedes-AMG SL65 Engine

The original 300SL inspired the elegant 190SL, and the later “Pagoda” version, designed by Paul Bracq, stood out for its lithe, compact shape. The R129, launched in 1989, was the epitome of sleek modernism. But something went wrong with the current model, which debuted for 2013. We’ve previously called it “slightly awkward” and noted that it broke a long line of beautiful design. No one at Mercedes-Benz has been particularly eager to defend its aesthetics since former design chief Peter Pfeiffer retired.

The raw specs stay the same for both. The twin-turbo, 6.0-liter V12 in the SL65 still posts 621 horsepower and 738 pound-feet of torque. A slight tune means the hand-built motor doesn’t let every one of its horses out of the corral until 5,500 rpm, instead of the 4,800 to 5,400-rpm window of before. All 738 pound-feet of torque show up to the party from 2,300 rpm to 4,300 rpm. The 5.5-liter, twin-turbo V8 in the SL63 continues to ‘make do’ with 577 hp and 664 lb-feet of torque. Acceleration times stay the same for both cars: 3.9 seconds from 0-60 in the SL65, 4.0 seconds in the SL63.

The new front end looks better here than on the SL450 and SL550 models because it was designed as an AMG face, then toned down for mortals who aren’t addicted to horsepower. The only differences are in the details, but they make all the difference: chrome edging on the outer intakes, a chrome edge on the splitter running the width of the car. The mesh treatments differ, too – instead of the tightly patterned dots and hexagonal plastic on the SL450, the SL65 gets a wide-open arrangement of dashed lines in the grille, and a mere two crossbars astride the lower intakes. The locomotive they shield needs a lot of air.

It’s demeanor likely gets another boost from the Designo Selenite Grey Magno paint, one of the new colors for 2017 along with Brilliant Blue. Still, we hope Mercedes can work more elegance into that flat, upright stance come the next generation. We miss the dramatic slope and angled planes of the previous generation R230 SL.

2017 Mercedes-AMG SL65 Interior

Further back, the side skirts form a single continuous wedge instead of consisting of two design elements, high-gloss chrome on the SL65 separating it from the silver chrome on the SL63. You can dip the whole thing in black with a new Night Package, or just tone down the brightwork with an extended carbon-fiber package. The SL63 gets 19-inch wheels all around, while the SL65 ups the rear wheel size to 20s.

The SL65 is Germany’s high-speed train, made to span countries and continents at speeds normally followed by the phrase “in a vacuum.” Yes, that country has the InterCityExpress, which is far roomier than the two-seat convertible, but the SL65 has the same top speed (186 miles per hour), a nicer interior, and can go more places. The diamond-stitched Nappa leather gets a new AMG Performance steering wheel, but there wasn’t anything else to add because it’s all already there – the only interior options on the US-spec 2016 car are a wood steering wheel and the Splitview Entertainment System.

Unlike the InterCity Express, the SL65 isn’t afraid of a tight turn. The SL63 is the feisty brawler, its AMG Speedshift MCT seven-speed transmission graced with faster reflexes and a double-declutch action when downshifting, as well as an available Performance suspension. The SL65’s torque figure means it sticks with the AMG Speedshift Plus 7G-Tronic automatic, but both convertibles get new variable electromechanical steering, revised Dynamic Select programming, and a rear differential lock standard. Turn the dial to Sport+ and start tapping the shift paddles, the SL65 will cleave through corners with savvy efficiency that masks its curb weight of well beyond two tons. The optional carbon ceramic brakes, still touchy on initial bite, can get you out of trouble almost as quickly as 621 hp can get you into it, and 738 lb-ft at just above idle launches you out of bends roaring like a fusillade.

But that’s not the intended brief here. As good as it ever was and now better looking, you really need hundreds of miles of unrestricted highway to imbibe the meaning of AMG’s capital convertible. Once autonomous driving reaches the SL65, nothing will get you closer to owning your own locomotive.

2017 Mercedes-AMG SL65