McLaren P1 supercar to debut as plug-in hybrid

McLaren will debut its P1 supercar at the Geneva auto show in March, with a surprising plug-in hybrid powerplant.

Wayne Cunningham Managing Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
Wayne Cunningham
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McLaren P1
McLaren has been track-testing its P1 supercar, but only now revealed its plug-in hybrid drivetrain. McLaren

When McLaren showed off its P1 supercar as a concept at last year's Paris Motor Show, I predicted it would have a similar engine to McLaren's other car, the MP4-12C. Turns out I was half right.

McLaren announced that the P1, which receives its production debut at the International Motor Show in Geneva the first week of March, will host not only a twin-turbo 3.8-liter V-8, but an electric drive motor as well.

The P1 will be a plug-in hybrid, joining other production cars such as the Toyota Prius Plug-in and the Ford C-Max Energi. Crazy, right?

Not so crazy when McLaren can announce specifications such as 903 horsepower and 664 pound-feet of torque.

By itself, the engine produces 727 horsepower, showing refinement over the similarly configured MP4-12C's engine, which produces a mere 592 horsepower. The electric motor, which is integrated with the engine, rates at 176 horsepower.

I suspect McLaren's total horsepower figure does not come from a dynamometer, but from adding the engine's and motor's output. When companies such as Ford or Toyota specify horsepower for their hybrids, they supply a number lower than the added engine and motor output. However, given the P1's seven-speed dual-clutch transmission, adding the numbers may be a valid manner of determining total horsepower.

The downside of this hybrid system is the addition of a 212-pound lithium ion battery pack and its associated cooling mechanism. However, McLaren says it fit the battery low into the carbon fiber monocoque, integrating it tightly with the car.

McLaren has not released acceleration or fuel economy numbers, but says the P1 will be able to drive 6 miles on electric power alone, letting it access zero-emission zones in European cities. The battery can, of course, be recharged from the grid and via regenerative braking.

If you want speed rather than fuel economy, the P1 includes an Instant Power Assist System (IPAS), activated by a button on the steering wheel. The IPAS makes all the battery's electricity available for acceleration.

In more typical driving scenarios, McLaren says the electric drive system eliminates turbo lag.

Another button on the steering wheel, labeled DRS for Drag Reduction System, adjusts the rear wing for less downforce.

The McLaren P1 will be shown on March 5 at the 2013 Geneva auto show.

McLaren P1
The battery pack adds 212 pounds to the P1. McLaren