McLaren Speedtail: Shocking speed

The otherworldly McLaren Speedtail tops 250mph and does 0-186mph in 13 seconds thanks to some very clever battery tech

THERE'S fast, and then there's McLaren Speedtail fast. This otherworldly car, billed by the British company as a 'hybrid hyper-GT' tops 250mph.

That's bonkers enough, but it's the acceleration that is really astounding. How does 0-186mph - though the metric equivalent, 300km/h, has a better ring to it - in 13 seconds sound?

Although it's obviously an aerodynamic device, McLaren says the Speedtail's hybrid set-up is what makes it capable of such outrageous performance.

The powertrain pairs a 4.0-litre turbocharged V8 with an electric drive unit to produce a total of 1,055bhp and 858lb.ft of torque.

The engine alone contributes 747bhp and 590lb.ft, but it is the electrified part of the car that gives it real kick.

McLaren hasn't yet said anything about the battery's storage capacity.

The electric motor, however, generates more than 230kW - around 310bhp - and all sorts of know-how from motorsport helps with the management of the system.

Keeping batteries cool, for example, is a particular challenge for electrified cars because their performance depletes the warmer they get. The Speedtail's battery cells are thermally controlled "by a dielectrical cooling system and permanently immersed in a lightweight, electrically insulative oil which quickly transfers heat away from the cells".

It's the first time a system like this has been used in a production road car, and it allows the cells to worker harder and for longer.

Proof that this works, says McLaren, can be found in how the Speedtail was able to hit its 250mph top speed more than 30 times during validation testing in the United States. Earlier electrified cars would have wilted in such repeatability tests.

McLaren plans to build 106 examples of the three-seat Speedtail, with each costing at least £1.75 million.