2012 Infiniti M35h hybrid sedan

2012 Infiniti M35h hybrid sedan

Almost a year ago, Infiniti confirmed a hybrid version of its new M sedan, to be launched at the end of 2010. Now, the company has unveiled that car, in the tony surroundings of the Pebble Beach Concours d'Elegance, the premier U.S. showcase for classic cars.

Infiniti has adopted the Lexus convention of denoting its hybrid models with a quiet, discreet, lower-case letter "h" as a suffix, so the new car will officially be the 2012 Infiniti M35h.

Driver's hybrid with high-tech steering, brakes

The company calls the M35h a "driver's hybrid," with innovations in both steering and braking technologies designed to blend fuel efficiency with driving feel.

Nissan Electro Hydraulic Power Steering System

Nissan Electro Hydraulic Power Steering System

The electro-hydraulic steering only activates the electric motor that powers the hydraulic-assist pump when the wheel is turned.

That gives the driver the familiar feel of hydraulically assisted steering, but only draws power when it's needed.

Lithium-ion battery pack

Infiniti's Electric Driven Intelligent Brake system generates power to recharge its 1.3-kilowatt-hour an astoundingly large 13-kilowatt-hour lithium-ion battery pack.

But while regenerative braking has been standard on hybrids since the start, Infiniti also uses electric motors to operate the wheel cylinders, a first for the U.S. market.

Decoupling the V-6 engine

The 3.5-liter V-6 engine generates 301 horsepower and 258 foot-pounds of torque. To complement the electric motor, it is adapted to run on the Atkinson cycle, in which valve timing is used to simulate a cycle in which the piston moves through strokes of different lengths, extracting more energy from the fuel than a conventional engine.

The engine and seven-speed automatic transmission are separated by a large 50-kilowatt (68-horsepower) electric motor that can power the car alone at speeds up to 60 mph, assist the engine in delivering torque to the wheels, and recharge the battery on overrun.

A pair of clutches bracketing the electric motor allows the engine to be totally decoupled from the transmission, leaving only the motor to power the transmission, but also letting the motor recharge the battery when the car is at a stop.

On sale: Spring 2011

Infiniti hasn't released combined engine and motor power output, performance data, or gas-mileage ratings for the 2012 M35h. But it is shooting for a 20-percent overall improvement, though it didn't say over which model; the M37 gets a combined EPA rating of 21 mpg.

Expect those figures, and final model details and options, closer to the Spring 2011 sale date.

For High Gear Media's full roster of stories from the Pebble Beach Concours and surrounding events, see our index page of all Concours coverage.

[Motor Authority]