The Porsche 911 Turbo (991) is the successor to the 997 Turbo and was released to mark the 40th anniversary of the 911 series. This sixth generation 911 Turbo was first shown at the 2013 Frankfurt Motor Show in Germany. The 991 boasts an improved power-to-weight ratio compared to older models and an improved all-wheel drive system. These changes increase the overall agility of the 911 Turbo to the point of it being capable of beating the Nürburgring time set by the Porsche Carrera GT.