The 720S is only fractionally longer and wider than the 570S, and uses the same ‘Monocell II’ carbon fibre passenger cell underneath. It’s shape also makes it one of McLaren’s most aerodynamic models ever, which could be the main motivation for the brand using a 720S inspired design for the Sports Series models.
The exact specifications of what’s under the skin of these prototypes remains closely under wraps. Rumours strongly suggest that the Woking car maker will be switching to V6 power for the new hybrid system, saving weight and increasing efficiency, with electric power more than making up for the loss in cylinder capacity.
The Sports Series replacement is also expected to come with a charging port, making it a plug-in hybrid rather than the recuperative hybrid system found in the P1. It will also put both petrol and electric power through the rear wheels only.
While it won’t be possible to fully cancel out the weight penalty of a hybrid system, Flewitt hopes to minimise it. “I’ve always said my ambition was to launch the hybrid at the same weight as the outgoing car,” he told Autocar last year.
“We’re not going to hit that, but we’re going to be within 30-40kg. When you think the P1 hybrid system was 140kg, we’ve done a huge amount to manage the weight. I’ve driven a prototype of it and the car is very compelling. We wouldn’t be launching it if it wasn’t going to be.”