A New Generation Lean Gasoline Engine for Premium Vehicle CO<sub>2</sub> Reduction

Abstract

<div class="section abstract"><div class="htmlview paragraph">In an era of rapidly increasing vehicle electrification, the gasoline engine remains a vital part of the passenger car powertrain portfolio. Lean-burn combustion is a formidable means for reducing the CO<sub>2</sub> emissions of gasoline engines but demands the use of sophisticated emissions control.</div><div class="htmlview paragraph">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; the boosting system comprises a variable geometry turbocharger and a 48 V electrical supercharger.</div><div class="htmlview paragraph">The work reported formed 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 CO<sub>2</sub> emissions by 15% under Euro 6d RDE (Real Driving Emissions) legislation and with particle number emissions measured down to 10 nm.</div><div class="htmlview paragraph">This paper will give a detailed treatment of the multi-cylinder engine and vehicle development undertaken. The engine delivered BSFC benefits exceeding 10% and a peak brake thermal efficiency of 42%, while the vehicle demonstrated a NO<sub>x</sub> conformity factor below 1.0 in independent RDE tests.</div></div>