2013 Mercedes-Benz SL 63 AMG Spied Testing

Following spy photos obtained earlier this year of the upcoming next-generation Mercedes-Benz SL-Class, these new photos today reveal that the AMG version of the stylish coupe-convertible range is also well into development.

Every bit as heavily camouflaged as its regular SL sibling, the SL 63 AMG spied here features larger intakes and bigger cross-drilled brake discs with larger calipers.

The new SL range is expected to draw styling cues from the the model line's range-topping SLS AMG, including the nearly 90-degree grille and vertically-opposed headlights.

Comparisons with the current SL - built on a platform now some nine years old - the spied test car appears to carry a lower, wider stance, pointing to higher-performance intentions.

Likely to draw power from Mercedes' new 5.5 litre twin-turbo V8 engine, the range-topping SL is expected to retain AMG's '63' badging.

Featuring direct-injection, the new smaller-capacity twin-turbo-charged V8 produces 400kW and 800Nm of torque, bettering the naturally-aspirated 6.2 litre engine's 390kW and 630Nm of torque.

Already doing service in the new S 63 AMG, Mercedes-Benz says the new engine offers a 25 percent improvement to fuel consumption, using just 10.5 l/100km. The 0-100km/h sprint is covered in a claimed 4.5 seconds - one hundredth of a second faster than the current model.