Fuel consumption and CO2 emissions from passenger cars in Europe – Laboratory versus real-world emissions
Abstract
Official laboratory-measured monitoring data indicate a progressive decline in the average fuel consumption and CO2 emissions of the European passenger car fleet. There is increasing evidence to suggest that officially reported CO2 values do not reflect the actual performance of the vehicles on the road. A reported difference of 30–40% between official values and real-world estimates was found which has been continuously increasing. This paper reviews the influence of different factors that affect fuel consumption and CO2 emissions on the road and in the laboratory. Factors such as driving behaviour, vehicle configuration and traffic conditions are reconfirmed as highly influential. Neglected factors (e.g. side winds, rain, road grade), which may have significant contributions in fuel consumption in real world driving are identified. The margins of the present certification procedure contribute between 10 and 20% in the gap between the reported values and reality. The latter was estimated to be of the order of 40%, or 47.5gCO2/km for 2015 average fleet emissions, but could range up to 60% or down to 19% depending on prevailing traffic conditions. The introduction of a new test protocol is expected to bridge about half of the present divergence between laboratory and real world. Finally, substantial literature was found on the topic; however, the lack of common test procedures, analysis tools, and coordinated activity across different countries point out the need for additional research in order to support targeted actions for real world CO2 reduction. Quality checks of the CO2 certification procedure, and the reported values, combined with in-use consumption monitoring could be used to assess the gap on a continuous basis.
- Publication:
-
Progress in Energy and Combustion Science
- Pub Date:
- May 2017
- DOI:
- 10.1016/j.pecs.2016.12.004
- Bibcode:
- 2017PECS...60...97F
- Keywords:
-
- CO<SUB loc="post">2</SUB> emissions;
- Certification cycle;
- Real-world driving;
- Fuel consumption gap;
- Passenger cars;
- 10-15 mode;
- Japanese Test Cycle;
- Phased Out From 2005 To 2011;
- A/C;
- Air Conditioning;
- ACEA;
- Association des Constructeurs Européens d'Automobiles - European Automobile Manufacturers' Association;
- ADAS;
- Advanced Driver Assistance Systems;
- ARS;
- Average Rectified Slope;
- ARTEMIS;
- Assessment and Reliability of Transport Emission Models and Inventory Systems;
- CO;
- Carbon Monoxide;
- CO<SUB loc="post">2</SUB>;
- Carbon Dioxide;
- CoC;
- Certificate Of Conformity;
- COPERT;
- Emissions Calculation Tool;
- C<SUB loc="post">w</SUB>;
- Air drag coefficient;
- DISI;
- Direct Injection Spark Ignition;
- E2HPAS;
- Energy Efficient Hydraulic Power Assisted Steering System;
- E10;
- Fuel containing 10% ethanol;
- E85;
- Fuel containing 85% ethanol;
- EC;
- European Commission;
- EEA;
- European Environment Agency;
- EHPAS;
- Electro – Hydraulic Power Assisted Steering;
- EPA;
- Environmental Protection Agency;
- EPAS;
- Electric Power Assisted Steering;
- EU;
- European Union;
- EUDC;
- Extra-Urban Driving Cycle;
- EV;
- Electric Vehicle;
- FTP;
- Federal Test Procedure;
- GDP;
- Gross Domestic Product;
- GHG;
- Green House Gases;
- GPS;
- Global Positioning System;
- HBEFA;
- Handbook emission factors for road transport;
- HC;
- Hydrocarbons;
- HDV;
- Heavy Duty Vehicle;
- HPAS;
- Hydraulic Power Assisted Steering;
- HWFET;
- Highway Fuel Economy Test;
- ICT;
- Information And Communications Technology;
- IEA;
- International Energy Agency;
- IRI;
- International Roughness Index;
- JC08;
- Japanese Test Cycle;
- Phased In From 2005 To 2011;
- JRC;
- Joint Research Centre Of The European Commission;
- LDV;
- Light Duty Vehicles;
- LED;
- Light Emitting Diode;
- MPG;
- Miles Per Gallon (US Or UK Gallon);
- MPI-SI;
- Multipoint Injection -Spark Ignition;
- NEDC;
- New European Driving Cycle;
- NO<SUB loc="post">x</SUB>;
- Nitrogen Oxides;
- OEAMTC;
- Österreichische Automobil-;
- Motorrad- Und Touringclub;
- OEM;
- Original Equipment Manufacturer;
- PC;
- Passenger Cars;
- PEMS;
- Portable Emissions Measurement System;
- PM;
- Particulate Matter;
- RMS;
- Root Mean Square;
- RPM;
- Revolutions Per Minute;
- RR;
- Rolling Resistance;
- RRC;
- Rolling Resistance Coefficient;
- SC03;
- US driving cycle designed to measure exhaust emissions with the use of air-conditioning;
- SFTP;
- Supplemental Federal Test Procedure;
- SUV;
- Sports Utility Vehicle;
- UDC;
- Urban Driving Cycle;
- UDDS;
- Urban Dynamometer Driving Schedule;
- UK;
- United Kingdom;
- UN;
- United Nations;
- UNECE;
- United Nations Economic Commission For Europe;
- US06;
- US driving cycle designed to measure exhaust emissions at high speeds and aggressive driving;
- VW;
- Volkswagen;
- WD;
- Wheel Drive (number of powered wheels);
- WLTC;
- Worldwide harmonized Test Cycle;
- WLTP;
- Worldwide harmonized Light Vehicle Test Procedure;
- WMTC;
- Worldwide harmonized Motorcycle Emissions Certification/Test Procedure.