| Nissan has announced the development of two
new 4-cylinder gasoline engines and a new continuously variable transmission
(CVT). The new hardware units will be successively adopted on various
small passenger cars, beginning with a new model scheduled for release
in Japan this autumn.
The two newly developed engines, the 1.5-litre HR15DE and the 2.0-litre
MR20DE, are both in-line 4-cylinder units, jointly developed by Nissan
and Renault for use in both companies' passenger cars.
Application of the HR15DE engine will begin with Nissan's all-new Tiida
model which will go on sale in Japan this autumn, while the MR20DE engine
will first be applied to a new minivan scheduled for release later this
year. Both engines incorporate a host of new shared technologies and are
designed to provide excellent fuel economy combined with improved acceleration
under the conditions most commonly encountered in everyday driving.
Specifically, the adoption of the following new technologies has substantially
improved fuel economy and torque under ordinary driving conditions:
1. The combustion period has been shortened and thermal efficiency improved
by strengthening the gas flow in the combustion chamber.
2. Some of the world's most advanced technologies have been employed to
reduce friction, including the use of a new machining method for the cylinder
bores and the application of a mirror-like finish to the crankshaft and
cam bearing surfaces.
3. The load imposed on the engine to drive the air conditioner and other
auxiliary units has been reduced by enhancing their efficiency and improving
the control programme.
The newly developed CVT further enhances the benefits that characterise
this type of transmission, including excellent fuel economy, smooth power
delivery without any shift shock and outstanding acceleration performance.
In particular, shift response has been improved by tuning the hydraulic
and electronic controls. The shift response improvement combined with
a wider gear ratio range contributes significantly to the acceleration
and fuel economy under ordinary driving conditions.
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