A New Generation Lean Gasoline Engine for Premium Vehicle CO2 Reduction

In an era of rapidly increasing vehicle electrification, the gasoline engine still remains a vital part of the passenger car powertrain portfolio. Lean-burn combustion is a formidable means for reducing the CO2 emissions of new gasoline engines, but demands the use of sophisticated emissions control. A 2.0 litre turbocharged direct-injection gasoline engine has been developed with a lean homogeneous combustion system matched to a robust lean and stoichiometric-capable exhaust aftertreatment. The aftertreatment system includes an SCR system and a GPF with filtration down to 10 nm particle size. The engine is equipped with a continuously variable valve-lift system, high-tumble ports and a high-energy ignition system, and the boosting system comprises a variable-geometry turbocharger and a 48 V electrical supercharger. The work reported forms part of the PaREGEn (Particle Reduced, Efficient Gasoline Engines) project under the Horizon 2020 framework programme. In this project, further development of gasoline engines as used in mid to premium-sized cars was undertaken, with the objective to reduce CO2 emissions by 15% under Euro 6d RDE legislation and with particle number emissions measured down to 10 nm. This paper will give a detailed treatment of the multi-cylinder engine and vehicle development undertaken.