The SLS AMG road car was introduced at the 2009 Frankfurt Motor Show as the first Mercedes-Benz automobile designed and built entirely by AMG from scratch. The production car used a front-mid-mounted 6.2-litre naturally aspirated V8 engine coded M159 — a substantially modified version of the M156 block featuring over 120 engineering changes including a dry-sump lubrication system — producing 420 kW. Distinctive gullwing doors that opened on gas struts were a central styling element, consciously referencing the iconic Mercedes-Benz 300SL Gullwing of the 1950s.
The GT3 racing variant emerged quickly from the road car programme. Development testing began at the Lausitz Eurospeedway in June 2010, and the car was officially introduced at the 2010 New York International Auto Show. After FIA homologation, customer deliveries began in February 2011. A total of 86 cars were sold over the production run.
The SLS AMG GT3 retained the road car's 6.2-litre naturally aspirated V8, adjusted to comply with GT3 Balance of Performance regulations. Significant racing modifications included a sequential six-speed transmission with steering-column-mounted shift paddles, an integrated multi-disc locking differential with traction control, extensively adjustable suspension — covering spring rates, shock absorber settings, ride height, stabiliser bars, track width, and camber — and a rack-and-pinion steering system with a more direct ratio than the road car. The braking system used steel discs with racing ABS. The driver sat in a carbon-fibre high-strength safety cell equipped with HANS device provisions and a six-point racing harness. AMG 18-inch light-alloy wheels replaced the road car's 19/20-inch units.
The SLS AMG GT3 first competed in the VLN Nürburgring Endurance Championship in 2010, admitted to the SP9 class with Balance of Performance set to 1,350 kg and 409 kW. It won its first race in October of that year.
From 2011 onwards, the car appeared in GT competitions across the globe. Championships where it competed included the FIA GT3 European Championship, the Blancpain Endurance Series, the Blancpain Sprint Series, the VLN, the 24 Hours of Nürburgring, the British GT Championship, Super GT, the Australian GT Championship, the Bathurst 12 Hour, the Dubai 24 Hour, the Macau GT Cup, and the Pirelli World Challenge.
Black Falcon Racing won the Dubai 24 Hour in both 2012 and 2013 with the SLS AMG GT3. In Super GT's GT300 class, drivers Haruki Kurosawa and Hironori Takeuchi finished joint fifth in the 2012 GT300 drivers' championship. At the 2013 Liqui Moly Bathurst 12 Hour, Erebus Motorsport took victory with the car, driven by Peter Hackett among others; the same year, another SLS AMG GT3 set the fastest lap and won the 2013 24 Hours of Spa, marking the first Mercedes victory in that race since 1964.
The SLS AMG GT3 was also used in the AMG Driving Academy programme. In the United States, Black Swan Racing and DragonSpeed ran the car in the SCCA Pirelli World Challenge.
A special limited edition, the SLS AMG GT3 "45th ANNIVERSARY", was unveiled at the 2012 São Paulo International Motor Show to commemorate 45 years of AMG, with five units built in a distinctive matte graphite colour. The engines for this edition were assembled by racing driver Bernd Schneider.
The standard SLS AMG served as the official Formula One Safety Car from the 2010 season through 2014. The base SLS AMG coupé was used in 2010 and 2011, with the SLS AMG GT variant taking over mid-2012 and continuing through the end of the 2014 season, coinciding with the end of the SLS AMG production run.
The SLS AMG GT3 established Mercedes-AMG's customer racing programme as a globally competitive force in the GT3 category during the early 2010s. Its victories at high-profile endurance events such as Bathurst and Spa were significant achievements for customer teams, demonstrating the car's speed and reliability at the highest level of privateer GT racing. The car was succeeded in Mercedes-AMG's GT3 customer racing line by the Mercedes-AMG GT3, introduced in 2015.