Sabre: A cost-effective engine technology combination for high efficiency, high performance and low CO2 emissions

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. © Lotus Engineering, 2009.