Seven minutes. That's all the time we've been allotted behind the wheel of the 2012 NISSAN INFINITI
M35 Hybrid at Nissan's Oppama proving ground just outside of Yokosuka City, Japan. The near-production spec car we've come all this way to spend a paltry 420 seconds driving is a hugely significant vehicle for Nissan's luxury arm, as it's the manifestation of some six years of development, millions of testing miles, and billions of yen invested.
The M35 Hybrid is Infiniti's first vehicle powered by Nissan's all-new, in-house-designed, full parallel hybrid powertrain, which comprises a 3.5-liter V-6 engine working in conjunction with a single electric motor and two clutches. Nissan
will initially launch the new system in its Japan-market NISSAN FUGA
sedan this fall. We'll get it next spring at a price set somewhere between the M37x all-wheel drive ($49,275) and base M56 ($58,425), which is in the neighborhood of its main bogey -- the Lexus Gs
450h ($58,325). Not surprisingly, it will also be Infiniti's cleanest ride ever.
At the press event, a Nissan
engineer outlined the M Hybrid's secret sauce: a gas engine/electric motor combo with twin clutches -- one dry, one wet. The former finds a home between the 3.5-liter Atkinson-cycle combustion engine (good for 302 horsepower) and the lithium-ion-battery-powered electric motor (67 horsepower). The dry clutch sits last on the same propshaft as the motor and seven-speed automatic transmission, and is always engaged. Basically, the lineup goes, from front to rear: gas engine, dry clutch, electric motor, transmission, wet clutch (see diagram below).
As with all hybrids, the idea is to rely on electric power as often as possible; Nissan's technique employs the twin clutches to decouple the gas engine from the transmission, which shuts off the engine completely. This approach nixes the need for a torque converter and allows for the direct application of power to the rear wheels (the only drive layout) -- further aiding throttle response and acceleration. Nissan
claims there is no mechanical drag when the engine is shut down, so the whole package remains efficient and clean. A specially calibrated ECU orchestrates system reactivity and fluidity, and regulates engine idle to reduce fuel consumption.
There are four drive modes continuously transitioning during operation, depending on speed and driving behavior:
Scenario 1: Combustion Engine Off, Electric Motor On -- gradual acceleration, low-speed urban driving. First clutch disengaged, engine shut off, second clutch engaged. Motor drives rear wheels and uses power from the lithium-ion battery pack.
Scenario 2: Engine On, Motor Off -- mid to high speeds. Both clutches engaged. The engine powers the wheels, while the wheel motion and motor help the recharge the batteries. The gearbox's high final gear ratio also aids efficiency.