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Possibilities for Reducing Pollution Emissions and Fuel Consumption During Warm-Up of Carburetted Engines for Motor Vehicles
Technical Paper
785004
Sector:
Language:
German
Abstract
Exhaust and fuel characteristics during the warm-up phase of
engine operation is in great need of improvement, especially for
carburetted engines. Due to the number of short trips made by
vehicles, a large proportion of urban driving occurs during warm-up
operation.
The paper presents possibilities for achieving these
improvements through modification of engine components (e.g.,
exhaust recirculation, oil and intake manifold heating). Tests were
conducted on an Audi 80 LS. Through use of the described changes,
fuel consumption beyond normal, hot-operation figures was reduced
from 25% to only a few percent of the latter. Reductions of CO and
HC emissions were 80% and 50%, respectively, although the erratic
engine performance which is often characteristic of warm-up
operation was somewhat aggravated. However, the results indicated
that the problems associated with engine warm-up can be solved at
acceptable costs. Further possibilities for improvements remain to
be studied.