It has been over a year since McLaren presented the 403kph Speedtail to the world. It is its most expensive and fastest production model and now, the Woking carmaker has finally revealed details about its incredible performance.

Featuring the M840TQ powertrain, its 4.0-litre V8 and electric drive unit create up to 1,055 horsepower and 1,150Nm of torque. It can go from 0-300kph in 13 seconds. A new lightweight air-intake system, improved cylinder head cooling, and a revised piston design contribute 757 horses and 800Nm of ‘traditional’ petrol-powered output to the Speedtail.

Speed machine! The Speedtail is blessed with 1,055 horses - 308 of which are produced by its electric motor alone... Photo: McLaren

McLaren says the single electric motor generates 308 horsepower on its own, which is an astounding figure for its application. The tech on display here is derived from Formula E, and McLaren is claiming it’s the “highest performing installation — including cooling and integration — of any electric motor currently in use in a production road car.”

The Speedtail’s cylindrical 1.647 kWh battery pack has a compact shape and is arranged in a ‘unique’ way. It delivers the best power-to-weight ratio of any battery pack in production today, and it has four times the power density of the battery in a McLaren P1.

Its battery cooling system is ‘thermally controlled by a dielectrical cooling system’ and are permanently submerged in electrically insulative oil which ‘quickly transfers heat away from the cells.’ According to McLaren, this innovative battery cooling system is the first in a production road car and allows the battery pack to push harder repeatedly without suffering degradation.

Just 106 units will be hand-built at the McLaren Technology Center in Woking, England with prices starting at around $2.3-million.