Improving fuel economy by 35% through combined turbo and supercharging on a spark ignition engine

The combination of boosting and downsizing is a well-known and efficient approach to reduce CO2 emissions of modern gasoline engines. The decrease of engine capacity and the increase of the specific performance helps to reduce the fuel consumption by limiting pumping, friction and heat energy losses.
Investigations in this area have been conducted by a collaborative research project called ‘ULTRABOOST’ which is co-funded by the UK Technology Strategy Board (TSB). The project consortium is made up of five industrial and three academic partners including Jaguar Land Rover (JLR) as lead partner, Lotus Engineering, Shell Global Solutions, GE Precision Engineering, CD-adapco, University of Bath, University of Leeds and Imperial College London.
In order to conduct research into the requirements of heavily downsized and highly boosted gasoline engines, the project consortium collaborated to produce a demonstrator engine bringing together the core competencies of each organisation to achieve the best overall system solution. This resulted in the development of a 2.0 Litre four cylinder gasoline downsized demonstrator engine capable of up to 35 bar Brake Mean Effective Pressure (BMEP), air pressure charging of up to 3.5 bar absolute and offering approximately up to 35% potential for the reduction of fuel consumption and CO2 emissions while still matching JLR’s 5.0 Litre V8 naturally aspirated (NA) engine performance figures.