Sabre: A Cost-effective Engine Technology Combination For High Efficie

ABSTRACT

Increasingly stringent tailpipe CO2 legislation and customer desire to reduce vehicle

fuel consumption are driving new technology developments, particularly in gasoline

engines. Many of these are not entirely complimentary to each other and all carry

various levels of on-cost to the vehicle, both in financial and systems complexity terms.

This paper will describe a downsized engine whose key technology packages include a

second-generation direct injection combustion system combined with turbocharging and

an integrated exhaust manifold (IEM). This engine has already been successfully

applied to a B/C class vehicle. The interaction of the engine technologies is described

together with the level of improvement in high-speed, high-load fuel consumption

possible when cooled EGR is employed. The impact of the IEM on the thermal load of

the vehicle is discussed in the context of what heat rejection would be expected from an

approach adopting cooled EGR in a similarly-powerful engine with a conventional

exhaust manifold is made. Finally, the level of performance increase possible with

differently-matched turbocharger systems is discussed as a means of illustrating the

applicability of the concept to other vehicle classes.