Conclusions
Port water injection to limit fuel-enrichment in a high performance turbocharged GDI engine is investigated in the paper. Despite the increase in engine complexity caused by the introduction of the water injection system, benefits are found in terms of combustion efficiency increase and related reduction in brake specific fuel consumption. In particular, the water/fuel operation is optimized thanks to 3D-CFD analyses and a case is found which is characterized by a knock tendency comparable to the original fuel-only engine, an increase of indicated power of about 2% and a reduction of the injected fuel around 17%, thus leading to an overall reduction of brake specific fuel consumption of nearly 20%.