| YOKOHAMA, Japan, July 6
YOKOHAMA, Japan, July 6 Nissan Motor Co (7201.T)
said it aims to nearly double the mileage on its first hybrid car
developed in-house compared with the gasoline engine version,
while keeping costs down with a simple, single-motor system.
Japan's No.3 automaker is due to launch a gasoline-electric
Infiniti M sedan, called Fuga in Japan, late this year, lagging
rivals Toyota Motor (7203.T) and Honda Motor (7267.T) by more
than a decade in offering a proprietary hybrid model.
While admitting to the late start, Nissan said its one-motor,
two-clutch system would achieve far better fuel economy, at a
much lower technical cost compared with hybrid leader Toyota's
complex, two-motor "series parallel" system.
"Typically, carmakers say the fuel economy improvement on
their cars using a 'strong' or 'full' hybrid system is roughly 30
percent, while for 'mild' hybrids (like Honda's), it's 15
percent," said Koichi Hayasaki, chief engineer of Nissan's
rear-wheel-drive hybrid system.
"We're aiming for an improvement of 60 to 90 percent," he
said, adding that the hybrid Infiniti M would have mileage
comparable to that of a compact car.
Nissan's hybrid system has a structure similar to that of
Volkswagen AG's (VOWG_p.DE), mounting an extra clutch that
separates the electric motor from the engine to allow for driving
using only electric power when the battery is charged.
But Hayasaki said Nissan's unique system enables it to better
control the motor by using a lithium-ion battery instead of
nickel-metal hydride, which is slower in capturing and
discharging energy. Using a lithium-ion battery, he said,
eliminates the need for a torque converter, which the Volkswagen
group uses on its Touareg SUV, Porsche Cayenne and other hybrids.
"It was a technical hurdle that most hybrid engineers in the
industry believed could not be cleared," Hayasaki said, adding
the system took about six years to develop.
Together with more accurate electronic controls, the system
allows the engine to idle more frequently and therefore use less
fuel. Hayasaki said millions of miles of testing had shown that
the engine was stopped about half the time in city driving.
By having fewer components, Hayasaki said, Nissan's hybrid
system was roughly 30 kg (66 lb) lighter than Toyota's series
parallel system, which mounts two electric motors and two
inverters, which make up the bulk of a hybrid system's cost.
As part of its drive to reduce carbon dioxide emissions from
its cars, Nissan is planning to also launch fuel-efficient 3- and
4-cylinder gasoline engines and stop-and-start technology this
The new March, due for launch in Japan this month, will be
the first to use the stop-start feature, which automatically
shuts down the engine when the car comes to a brief stop. The
March will have class-leading fuel economy of 26 km/litre, Nissan
Nissan, held 43 percent by France's Renault SA (RENA.PA), is
due to mass-market the zero-emission Leaf electric car starting
in December. Its sole hybrid model now is the Altima sedan, which
uses Toyota's hybrid system.
(Editing by Michael Watson)