Abstract:

SAIC Motor Corporation Limited (SAIC Motor) developed an all-new 1.5 L 4-cylinder turbocharged gasoline direct injection engine to meet the market demand and increasingly stringent requirement of regulations, by applying a series of advanced fuel efficient and emission reduction technologies, such as central gasoline direct injection, efficient turbo charging with low inertial, dual variable valve timing, integrated exhaust manifold, etc. The engine was equipped on a number of ROEWE and MG vehicles, and achieved the design objectives of low fuel consumption, high performance, good noise, vibration, harshness (NVH) and low emissions. The development of technology upgrades were carried out on the basis of this engine. The results show that the thermal efficiency is further improved while maintaining the same 250 Nm maximum torque level through combustion system optimization and application of miller cycle. The vehicle fuel consumption is reduced by 6.5% in New European Driving Cycle (NEDC). The turbo charger efficiency improvement and cylinder head block cooling optimization, maximum torque is improved through combustion system optimization from 250 to 275 Nm, and the low speed turbo response is improved by 25%. By the fuel spray pattern optimization and the 35 MPa high pressure fuel system development, the engine-out particulate numbers (PN) emission is substantially reduced, and the vehicle is capable of meeting Chinese standard VI b particulate emission regulatory requirement without gasoline particulate filter (GFP).

Key words: turbocharged gasoline engine, gasoline direct injection (GDI), Miller cycle, particulate numbers (PN) emission