Toyota will soon introduce vehicles globally
with a series of newly-developed, highly efficient gasoline engines that
achieve thermal efficiency and fuel efficiency improvements of at least 10pc,
according to a company statement. These developments may even benefit countries
like India where Toyota has a major presence, according to Motown India
magazine.
Toyota
is able to do develop these new engines using the combustion and loss-reduction
technologies it has refined in its dedicated hybrid engines. Two engines will
form the base of the new series. The first is a 1.3-litre gasoline engine using
the Atkinson cycle normally used in dedicated hybrid vehicles that achieves a
maximum thermal efficiency of 38pc — top-level among mass-produced engines. The
second is a 1.0-litre gasoline engine that has achieves maximum thermal
efficiency of 37pc.
The
new engines will be used in models scheduled for partial redesign in the near
future, and a total of 14 engine variations will be introduced globally by
2015.
The
use of the Atkinson cycle provides an increased expansion ratio and reduces
waste heat through a high compression ratio (13.5), resulting in superior
thermal efficiency. Toyota aims to further improve the fuel efficiency of the
engine by utilising other innovations including an intake port with a new shape
that generates a strong tumble flow (whereby the air-fuel mixture flows in a
vertical swirl) inside the cylinder, and a cooled exhaust gas recirculation
(EGR) system paired with Variable Valve Timing-intelligent Electric (VVT-iE)
technology to improve combustion and reduce loss. As a result, the new engine
will have a maximum thermal efficiency of 38pc ?top-level among mass-produced
engines. The new features, combined with idling stop and other functions, will
lead to fuel efficiency gains of approximately 15pc by comparison with current
vehicles.
Meanwhile,
a 1.0-litre engine jointly developed with Daihatsu Motor Co., Ltd. has achieved
maximum thermal efficiency of 37pc due to a similar tumble flow-generating
intake port, a cooled EGR system, and a high compression ratio. Combination
with the idling-stop function and various other fuel consumption reduction
technologies allows vehicles to achieve a maximum fuel efficiency improvement
of approximately 30pc over current vehicles.