WORKING PAPER 2018-14 Fuel-efficiency technology trend assessment for LDVs in China: Advanced engine technology Authors: Guowei Xiao, Zifei Yang, Aaron Isenstadt Date: 17 September 2018 Keywords: engine technology, fuel efficiency, passenger car 1 Background to advance post-2020 standards for of 3.2 L/100 km was set. To evaluate light-duty vehicles. whether and how these targets can be Fuel-consumption standards drive met, it is essential to understand what down China’s use of fuel by the In its “Made in China 2025” strategic technologies will be available within on-road sector and encourage the initiative (MIIT, 2015), China set a 2025 the 2020-2030 timeframe and what uptake of advanced vehicle-effi- fleet efficiency target of 4 L/100 km the costs of applying those technolo- ciency technologies. Understanding for passenger cars, a 20% decrease gies in the Chinese market will be. the need for a policy roadmap and from the 2020 target of 5 l/100km. In long-term strategies to provide cer- the Technology Roadmap for Energy This series of technical briefings tainty for long-term fuel consump- Saving and New Energy Vehicles aims to provide a comprehensive tion, technology advancement, and published by the Society of Automo- understanding of the current potential compliance costs for man- tive Engineers of China (SAE China, availability, effectiveness, and ufacturers, China is looking ahead 2016), a 2030 fleet efficiency target future market penetration of key ABBREVIATIONS 2-TCI Two stage CVVL Continuous variable IMA Integrated motor TCI Turbocharger with turbocharger with valve lift assist intercooler intercooler DCP D ual cam phasing IMG Integrated motor VCM Variable cylinder ACT Active cylinder DEAC Cylinder deactivation generator management technology DLC Diamond-like carbon ISG Integrated starter VCR Variable compression AFM Active fuel DSF Dy namic skip fire generator ratio management DVVL Discrete variable MDS Multi-displacement VGT Variable turbine AGM A bsorptive glass mat valve lift system geometry AVS Audi valve-lift EGR Exhaust gas MPI Multi-point injection turbocharger system recirculation NA Naturally aspirated VT-C Variable compression BMEP Brake mean effective GDI Gasoline direct OHC Overhead-cam ratio turbocharging pressure injection OHV Overhead-valve VTEC V ariable valve timing BSG Belt-driven starter GSG Geely Stop-Go PFI Port fuel injection and lift electronic generator HCCI Homogeneous SCI Supercharger with control CATC China automotive charge compression intercooler VVEL Variable valve event test cycle ignition SI Spark ignition and lift CCP Coupled cam ICP I ntake cam phasing SPCCI Spark controlled VVL Variable valve lift phasing compression ignition VVT V ariable valve timing Acknowledgments: The authors thank the Energy Foundation China for sponsoring this series of studies. We greatly appreciate the generous contributions of time by the following experts: Ameya Joshi (Corning), Peter Davies, Ning He (Honeywell), Sean Osborne (ITB), Akichika Yamaguchi (Denso), experts from MAZDA, and John German (the ICCT). © INTERNATIONAL COUNCIL ON CLEAN TRANSPORTATION, 2018 WWW.THEICCT.ORG FUEL-EFFICIENCY TECHNOLOGY TREND ASSESSMENT FOR LDVS IN CHINA: ADVANCED ENGINE TECHNOLOGY fuel-efficiency technologies that Fuel eciency manufacturers are likely to use in technologies China by 2030. This information enables a more accurate, China-spe- cific understanding of future technol- Advanced Vehicle Thermal Hybrids and ogy pathways. Transmissions engines technology management electrifction We group technologies into sev- eral categories: advanced engine, Figure 1 Categorization of fuel efficiency technologies in the briefing transmission, vehicle technologies, thermal management, and hybrids and 2 Introduction Since about 1980, ongoing devel- electrification (Figure 1). The specific opments in computer-aided design Internal combustion engines convert technologies we considered include and simulation, as well as on-board the chemical energy in fuel into vehi- those that are available today and electronic controls, have enabled rapid cle kinetic energy through specific others that are under development technology improvement to reduce thermodynamic cycles. The theoreti- and expected to be in production in these sources of energy loss. These cal maximum efficiencies of the ther- the next 5-10 years. technologies not only improve engine modynamic cycles indicate that not efficiency but also reduce vehicle This research relies on information all the fuel’s energy can be converted fuel consumption in other ways. For from publicly available sources, third- into vehicle movement. Indicated effi- instance, apart from its benefits in heat party databases, and information ciency is defined as the proportion losses and mechanical losses, turbo- from the participating partners. Our of fuel energy that gets transmitted downsizing can also reduce vehicle approach includes: to indicated work, or the work that fuel consumption by simply reducing the high-pressure in-cylinder gases the weight of the engine and lowering • A detailed literature survey, do to the pistons during an engine’s engine speed. Stop-start technology including both Chinese and global power stroke. Factors that affect an reduces fuel consumption by shutting regulatory documents, official engine’s indicated efficiency include off the engine during idling. Some announcements, and industry incomplete combustion and wasted advanced stop-start techniques are and academic reports. heat. Energy loss from incomplete also equipped with regenerative brak- • Analysis of databases from Polk combustion is negligible, but heat ing, which recovers energy from brak- and Segment Y. losses account for more than 60% of ing and uses it to power accessories, the fuel energy in current engines, reducing accessory losses. In this • Conversations with manufactur- half of which is wasted by the cool- section, we will evaluate technology ers, tier one suppliers, research ing system and half by exhaust gases. progress and new developments of entities, and domestic and inter- Moreover, not all the work done to key technologies. national experts. the pistons makes it to final engine shaft output. This conversion rate is For each key technology, we discuss 3 Current status how it reduces passenger-car fuel termed mechanical efficiency, since consumption, its effectiveness in the losses are basically due to move- 3.1 GASOLINE DIRECT reducing fuel consumption, and its ment of other components. Fac- INJECTION current level of application or poten- tors that result in mechanical losses tial application in the China market. include pumping air into and out of Gasoline direct injection (GDI) injects Wherever applicable, we compare the engine, friction, and powering highly pressurized gasoline into the technology trends in China with those accessories, such as the alternator, combustion chamber of each cylinder. in the United States and the European oil pump, water pump, and com- Since GDI provides direct cooling to the Union to reflect potential technology pressor for air conditioning. There in-cylinder charge via fuel vaporization, pathways in the long term. are also idling losses, although not it allows an increase in the compression directly reflecting engine efficiency. ratio of approximately 0.5 to 1.5 points This briefing assesses technology These losses are highly dependent by improving knock resistance relative progress and new developments in on the type of driving, so total losses to naturally aspirated or turbocharged internal combustion engines. can vary significantly. engines using port fuel injection (PFI) 2 INTERNATIONAL COUNCIL ON CLEAN TRANSPORTATION WORKING PAPER 2018-14 FUEL-EFFICIENCY TECHNOLOGY TREND ASSESSMENT FOR LDVS IN CHINA: ADVANCED ENGINE TECHNOLOGY (EPA, 2016a). In addition, the cooling 50% effect results in more trapped intake charge, thus increasing engine volu- IHS metric efficiency and engine power 40% and torque. GDI engines also improve exhaust scavenging at low engine speeds by increasing valve overlap 30% and delaying fuel injection until after CATARC the exhaust valve is closed, further Segment Y increasing engine power and torque at lower engine speeds. A study by 20% Chang’an (Zheng et al., 2016) shows that, by replacing the multi-point injec- tion (MPI) system of a 1.6L naturally 10% aspirated 4-cylinder engine with a GDI system, fuel consumption was reduced by 3.9% over the New European Drive 0% Cycle (NEDC) through increasing the 2009 2010 2011 2012 2013 2014 2015 2016 2017 compression ratio from 10.5:1 to 11.8:1. Furthermore, this replacement would Figure 2 Market penetration of GDI from different data sources increase engine torque by 5%-23% the Haval H6 model; Chery’s 1.6T GDI 3.2 COOLED EGR depending on engine speed, and engine is expected to appear on the maximum power by 4.5%. Some man- Commonly used on diesel engines as market in 2018; and in 2016 Chang’an a method to reduce emissions, cooled ufacturers are also pursuing dual injec- introduced its Blue Core 1.5L turbo exhaust gas recirculation (EGR) has tion by combining PFI and GDI. dual port injection (1.5 TDPI) engine, also been found effective for improv- which combines GDI and PFI on a In China, GDI penetration in the pas- ing fuel efficiency of gasoline engines. turbo engine (Chi, 2016). senger car fleet has increased rap- EGR systems introduce some of the idly. Although market penetration The uptake of GDI is much higher in engine-out exhaust gas into the intake estimates from different data sources