>> Monday, March 30, 2009
Nissan shows off some future tech tricks.
BY AARON ROBINSON
After years of pushing performance, Nissan is now scrambling to catch Honda and Toyota in the runaway green market. The company summoned journalists to its headquarters near Yokohama, Japan, for a peekaboo at forthcoming environmental and safety tech. Here’s an appetizer:
What: Rear-drive hybrid transmission for V-6 engines.When: 2010.How: Unlike Toyota’s hybrid transmissions, which are continuously variable, the Nissan transmission from Japanese supplier Jatco has seven speeds. A husky flywheel motor/generator sandwiched between the transmission and engine can be the sole source of power up to a lofty 60 mph before the engine switches on. There is no torque converter. Electrohydraulic clutches at both ends of the transmission govern power flow, allowing the motor to propel the car while decoupling the engine, the engine to stop and start while the car is rolling, and if necessary, the engine to charge the lithium-ion battery pack while the car is stopped. A supplemental electric pump supplies transmission- and clutch-oil pressures at stops.Driving: The 3.5-liter V-6 Nissan Skyline prototype (Infiniti G35 in the U.S.) steps off with a V-8’s snap on combined engine/electric power. Step lightly, and it accelerates on electric to 25–30 mph. Going faster on electrics alone requires a feather-light foot on the gas. Most EVs have no step gears, so the silent upshifts of the seven-speed feel strange. At a 60-mph coast, the engine will shut off. Nissan was mum on power output and fuel savings, but we estimate motor power in the 125-to-150-horsepower range and combined output at 350 to 375 horses, with combined fuel economy a couple of mpg below 30.
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