Two of the world's most advanced plug-in hybrid vehicles took to the track at the Goodwood Festival Of Speed.

Of course, we're talking of the Porsche 918 Spyder and the McLaren P1 (we'll take one of each).

Here's video of both of these stunning machines doing the 1.1-mile hillclimb at Goodwood.

Note that the 918 Spyder operates electrically throughout, while the P1 is going for best lap time and, as such, the ICE is fired up from the get go.