The rear-wheel-drive SL 43 is powered by a 2.0-litre four-cylinder turbocharged petrol engine, producing 375bhp and 354lb ft of torque. The model also benefits from a 12bhp boost from a 48V belt-driven starter-generator.
As standard, the SL 43 is equipped with an electric exhaust gas turbocharger, which, Mercedes says, is a world first for a series-production vehicle.
The technology, which is the same as that used on Mercedes-AMG F1 cars, adds a 4cm-thick electric motor to the turbocharger shaft. It drives the turbocharger directly, which, Mercedes claims, “significantly improves immediate response from idle speed and across the entire engine speed range.”
Mercedes says it provides the SL 43 with a more dynamic driving experience, optimising acceleration and accelerator input. It also maintains boost pressure when the driver has taken their foot off the accelerator.
The technology helps to propel the car from 0-62mph in 4.9sec and on to a top speed of 170mph. SL 43 models are also equipped with a nine-speed AMG Speedshift multi-clutch transmission.
Jochen Hermann, Mercedes’ chief technical officer, said: "The electric exhaust gas turbocharger is a fascinating example of the extensive transfer between Formula 1 technology and the development of production vehicles.
“In implementing this in conjunction with our powerful M139 four-cylinder, we were also able to draw on the enormous wealth of experience of our colleagues at Mercedes-AMG High Performance Powertrains. The technology increases agility and thus driving fun, while at the same time improving the efficiency of the drive system.”
Mercedes says the SL 43 features a slightly adapted exterior design, with rounded front and rear aprons. A set of 19in alloy wheels are fitted as standard, with the option to swap to 20in or 21in instead.
Inside, standard equipment includes the firm’s MBUX infotainment, various driver assistance systems, electric, faux leather seats and black gloss interior trim with aluminium and carbon highlights.
Prices have not yet been revealed for the SL 43, but the model will sit below the V8-powered SL 55 4Matic+, which produces 469bhp, and the 577bhp SL 63 4Matic+.