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Gasoline engine concepts related to specific vehicle classes
Technical Paper
2000-04-0394
Sector:
Language:
English
Abstract
The simultaneous reduction of conventional pollutants and CO2
requires the introduction of new sophisticated drivetrain
technologies. However, reduced fuel consumption results in
increased system complexity and production cost while the
development and application requirements increase
disproportionately.
The effectiveness of these different technologies greatly
depends on the load distribution. With dedicated vehicle classes
both load distribution and acceptable add-on costs vary
significantly, therefore the use of different appropriate
technologies represents the best solution.
In low-cost/low-power vehicles, variable-charge motion in
combination with high levels of EGR gives fuel economy improvements
with small add-on costs and production risk. Direct Injection with
stratified charge and Fully Flexible Variable Valve Timing, as
means of load control, offer the best fuel economy. However, they
also increase cost, complexity and the need for smaller production
tolerances. Thus, these technologies will be more often applied to
mid-size or large vehicles where the absolute fuel consumption
improvement is more significant and the add-on costs less
critical.