McLaren unveiled the super sports car at the Goodwood Festival of Speed. The 600LT (Longtail) is based on the 570S Coupé introduced in 2015, but is just over seven centimetres longer at 4,604 millimetres. Compared to the 570S, the 600LT is 100 kilograms lighter due to the generous use of carbon fibre, and has a dry weight of 1,247 kilograms. About a quarter of the parts have been changed compared to the 570S Coupé. The Longtail features an extended front splitter and rear diffuser, as well as a fixed rear wing.
The car is powered by an advanced 3.8-litre V8 biturbo engine that delivers 441 kilowatts (600 hp) at 7,500 rpm and a maximum torque of 620 newton metres at 5,500 to 6,500 rpm. A power-to-weight ratio of 354 kW/tonne allows the car to sprint to 100 km/h in 2.9 seconds, reaching a top speed of 328 km/h. The chassis components stem from the McLaren 720S, while the brake system with aluminium callipers and carbon ceramic discs comes from the McLaren Super Series. Production of the McLaren 600LT Coupé is strictly limited.