What a glorious morning for it! Normally the streets of London are filled with hybrids, especially the scores of Toyota Prius taxis, but this morning the capital played host to a different kind of hybrid car. That’s because FIA Endurance World Champion Mark Webber took his Porsche 919 Hybrid LMP1 car for a blast around London in the early hours.

The four-mile run took place around some of central London’s most iconic areas – taking in landmarks like the Houses of Parliament and Trafalgar Square before finishing just off Westminster Bridge. The low-slung Le Mans car wasn’t slumming it with other traffic, though, as a police escort was provided to stop the astonished drivers of regular cars, vans and buses getting too close.

Despite having a top speed of about 210mph courtesy of its 900bhp hybrid powertrain, the Porsche 919 Hybrid was forced to adhere to strict speed limits at all times – which played havoc with the car’s cooling systems. With no fans to keep the engine cool, it’s reliant on airflow through its system of ducts and vents – which is far less when you’re doing 15mph around Parliment Square than when you're topping 200mph on the Mulsanne Straight. Both the car and driver Mark Webber were feeling the heat.

Another challenge was visibility. With a cut-down windscreen and high wheelarches, Webber couldn’t take in any of the sights, instead having to concentrate on avoiding unseen kerbs.

The LMP1 car made this trip to promote its companion on the run – the new Porsche Panamera E-Hybrid, which also mixes petrol and electric tech to produce a slightly more pedestrian 455bhp.