HDV fuel economy certification approaches around the globe Dr. Felipe Rodríguez Geneva, January 7, 2019 HD CO2 & FUEL EFFICIENCY HARMONIZATION WORKSHOP 78th GRPE Meeting

Overview of HDV activities in the G20 Transport Task Group Outline Overview of HDV activities in the G20 Transport Task Group Overview of HDV CO2/FE certification approaches around the globe Comparison of EU and US methodologies Vehicle simulation tool Air drag determination Harmonization possibilities for HDV CO2/FE certification

Overview of HDV activities in the G20 Transport Task Group

What is the G20 Transport Task Group? A voluntary platform for G20 countries to share respective experience and work together to improve the energy and environmental performance of motor vehicles, especially HDVs.  Leading members: the EU and United States Participants: Argentina, Australia, Brazil, Canada, China, Germany, India, Italy, Japan, Mexico, Russia, and the United Kingdom IPEEC coordinates Transport Task Group and G20 activities ICCT and GFEI are implementing organizations

Current TTG activities Build domestic support and enhance capability for action to reduce the energy and environmental impacts of motor transport, especially HDVs. Deep Dives Identify and exchange best practices among G20 countries on the implementation of cost‑effective energy efficiency and emission control measures in the transportation sector. Policy Exchanges Conduct analysis and outreach to assess the opportunities, barriers, costs and benefits of HDV programs, and subsequently recommend a course of action for participating G20 countries. Research Agenda

TTG History Nov 2014 June 2015 Oct 2015 Sept2016 Jul 2017 June 2017 RESEARCH AGENDA Policies to reduce fuel consumption, air pollution, and carbon emissions from vehicles in G20 nations FOUNDED Australian G20 Presidency 2014 Nov 2014 2015 June 2015 Oct 2015 2016 Energy Ministers Communiqué TTG History POLICY EXCHANGES Under the Turkey G20 Presidency, energy ministers agree to further support the work of the TTG Continue policy exchanges over phone and webinar Sept2016 Jul 2017 June 2017 Jan 2017 2017 from 2014 to 2018 World Class Standards Under the China G20 Presidency, the Energy Efficiency Leading Programme encourages G20 members to work toward given examples of world-class clean fuel and vehicle standards Energy Action Plan RESEARCH AGENDA G20 Hamburg Climate and Energy Action Plan for Growth Impacts of world class vehicle efficiency and emissions regulations in select G20 countries Topics of recent policy exchanges EU Real Driving Emissions (RDE) Type Approval Test for LDVs Argentina’s energy efficiency programs in transport European Commission’s HDV CO2 Standards Proposal Aug 2017 2018 Sept 2018 2019 RESEARCH AGENDA Status of policies for clean vehicles and fuels in select G20 countries DEEP DIVE 6 month in-depth webinar series on HDV CO2 certification 1ST IN-PERSON TTG MEETING Argentina G20 Presidency

Objectives of the TTG Deep Dive project Support voluntarily participating G20 TTG members to: measure and certify heavy-duty vehicle (HDV) fuel consumption design and implement HDV labeling programs and standards tailor existing methodologies and simulation models (i.e. GEM and VECTO) to suit new regional contexts, obviating the need for brand new methods https://www.theicct.org/heavy-duty-vehicle-efficiency

Overview of HDV CO2/FE certification approaches around the globe

HDV standards developments around the globe 1/2 Type FE & CO2 (ex. Canada); CAFE FE; individual vehicle FE; CAFE CO2 Vehicle scope GVWR > 3.85t 19 sub-categories, by vehicle type / duty cycle and GVW GVW > 3.5t 66 sub-categories, by vehicle type / duty cycle and GVW 25 sub-categories, by type (bus/lorry) and GVW Undecided. Possible GVW>16 tonnes Rigid trucks and tractor trailers 4x2 and 6x2 Timeframe (full implementation) MY2014 Phase 1 MY2018 Phase 2 MY2014 China I MY2016 China II MY2021 China III MY2015 MY2025 (proposal) 2025 and 2030 (not yet adopted, standards proposal announced in 2018) Certification Engine dyno + component testing + whole vehicle simulation Chassis dyno (base vehicles) or whole vehicle simulation (variants) Engine dyno + whole vehicle simulation Aero/Rolling tests (proposal) Flexibilities ABT scheme None Averaging. Initial credit system; now reduced at half. Averaging and banking Enforcement Type approval ~Inspection / maintenance Under development Adapted from: White, B., & Hill, N. (2017). Analysis of fuel economy & GHG emission reduction measures from HDVs in other countries and of options for the EU. Ricardo Energy & Environment.

HDV standards developments around the globe 2/2 Type FE Undecided; possibly FE Undecided; likely both FE and CO2 Undecided; likely FE Vehicle scope >12t Segmentation on GVW, number of axles, and truck type (rigid – tractor) >3.85t Undecided >3.5t 4 sub-categories by duty cycle Timeframe (full implementation) Steering group since 2014 CSFC standards: 2018-21 Certification Track testing at 40/60km/h As US Phase 2 Flexibilities Under development Enforcement Evaluation Comments In force from April 2018 Proposal for HDV F/CO2 timeline: Phase 1 (2018-22). Phase 2 (2023-27) Phase 3 (2028-32): 2012 General Law on Climate Change requires vehicle efficiency standards Official announcement expected in near term Adapted from: White, B., & Hill, N. (2017). Analysis of fuel economy & GHG emission reduction measures from HDVs in other countries and of options for the EU. Ricardo Energy & Environment.

US and Canada HDV fuel consumption certification Coastdown test Wind average correction Tires test GEM - Engine cycle generation Engine testing: Cycle averaged map GEM Transient correction Standard vehicle specifications Engine dyno mapping Transmission and axle test Powertrain correction Powertrain testing option Off cycle technologies Declared CO2 and FC value Input data Dyno testing Correction Simulation Output data

Europe HDV fuel consumption certification Constant speed air drag test Transmission and axle test VECTO WHTC test Cross wind and speed profile correction Transient correction Tires test Vertical load correction Engine dyno mapping Auxiliaries Declared CO2 and FC value Input data Dyno testing Correction Simulation Output data

China HDV fuel consumption certification “Base” vehicle “Variant” vehicle Chassis dyno Coastdown test data Simulation modeling Engine dyno mapping Weighting factors to each vehicle type (e.g. bus, long-haul tractor) Run C-WTVC cycle: record FC on urban, rural, and motorway segments of cycle Measurement and calculation of fuel consumption Input data Output data Dyno testing Correction Simulation

Japan HDV fuel consumption certification Engine dyno testing Standard vehicle specifications Declared CO2 and FC value Simulation modeling Input data Output data Dyno testing Correction Simulation

(base vehicles tested, variants simulated) Most regions use HDV simulation in combination with component certification to determine CO2 emissions Rolling resistance, aerodynamic drag From Testing Standard Value Chassis dyno testing (base vehicles tested, variants simulated) Payload ~1/2 payload Full Payload Constant speed testing (40 and 60 km/h) Transmission and axle losses From Testing Powertrain dyno testing (Optional) Simulation Model Engine map From Testing Test cycles 3 cycles (weighted, incl. grade) 2 cycles (weighted, incl. grade) 1 cycle (‘mini-cycles’ weighted) 5 cycles (incl. grade)

Comparison of EU and US methodologies

Vehicle simulation models

”Fuel consumption simulation of HDVs in the EU: Comparisons and limitations” (2018) A comparison study of the latest releases of GEM and VECTO Although focused on VECTO, it describes the model architectures of both GEM and VECTO Just main results are shown in this presentation Rodríguez, F. (2018). Fuel consumption simulation of HDVs in the EU: Comparisons and limitations. International Council on Clean Transportation. https://www.theicct.org/publications/fuel-consumption-simulation-hdvs-eu-comparisons-and-limitations

Input comparison between GEM and VECTO Component VECTO input GEM input Engine Displacement, idle speed, fuel consumption map, full load torque curve, motoring friction curve, brake-specific fuel consumption over the Worldwide Harmonized Transient Cycle (WHTC) Displacement, idle speed, fuel consumption map, full load torque curve, motoring friction curve, fuel consumption over the ARB Transient Drive Cycle for 9 different vehicle configurations Transmission Transmission type, gear ratios, torque loss map as a function of torque and speed for each gear, maximum torque and speed per gear Transmission type, gear ratios, and maximum torque per gear. Optional: Power loss map as a function of torque and speed for each gear Axle Axle ratio and torque loss map as a function of torque and speed Axle ratio Optional: Power loss map as a function of torque and speed Aerodynamic drag Air drag area as determined during the constant speed procedure. For rigid trucks, a standard box is used. For tractors, a standard trailer is used. Air drag area as determined by the coastdown methodology. Standard trailers are used for tractor modeling. Tires Tire dimensions, rolling resistance coefficient (Crr), and load applied during the rolling resistance test for each axle Rolling resistance coefficient (Crr) for each axle, and drive tire revolutions per mile Vehicle Curb vehicle weight, gross vehicle weight rating, and axle configuration Vehicle weight reduction (sum of standardized weight reductions per component), vehicle regulatory subcategory (e.g., Class 8, sleeper cabin, high roof), and axle configuration Other Auxiliaries: Technology used for the following auxiliaries: cooling fan, steering system, electric system, pneumatic system, A/C system (whether it is present or not), and power take-off Off-cycle technologies: Improvements through the application of the following technologies: Speed-limiter, neutral-idle, intelligent controls, accessory load reduction, extended idle reduction, tire pressure system, and other technologies.

GEM’s model architecture GEM does not feature a graphical user interface. GEM was developed in Matlab Simulink as a forward-looking model: The simulation runs from the accelerator pedal to the wheels. The GEM architecture is comprised of four main modules: Powertrain, Vehicle, Driver, and Ambient. The Driver module is a closed-loop controller

VECTO’s model architecture VECTO was developed in C# as a backward-looking model: the simulation flow occurs in the opposite direction to the way it takes place in the actual vehicle. The Driver Model converts the drive cycle information into an acceleration request, to ultimately locate an appropriate operating point in the engine fuel map Once a valid engine operating point is found, the simulation moves to the next point in the driving cycle.

Comparison results: Constant speed cycles with grade The engine work is useful to gauge the agreement in energy flows observed by the engine. The fuel consumption is useful to assess the impact of the shifting strategies. For a given engine work, the shifting strategy determines the regions of the engine map. Absolute error: 0.64%

Comparison results: Transient cycle Despite the differences in model architecture (forward vs backward-looking), driver model, and shifting strategy; both VECTO and GEM produce similar results in terms of engine work and fuel consumption. Absolute error: 2.03%

Air drag certification

EU’s constant speed test for air drag measurement EU’s air drag test procedure (see EU 2017/2400 Annex VIII) measures the torque at the wheel at a high and a low speed to determine the air drag area (CdA in m2). The methodology requires the measurement of the torque at the wheel, the vehicle position, and the wind speed and angle as observed by the vehicle.

US’s coast-down test for air drag measurement The coast-down procedure that is followed in the United States it is described in §1037.528 The data measured in the coast-down test are the vehicle speed, the air speed and direction as observed by the vehicle. Furthermore, the road grade, wind speed and direction, ambient temperature, and atmospheric pressure as measured from a stationary weather station are also recorded.

Comparison of key points between US and EU air drag tests (1/2) Parameter EU constant speed US coastdown Torque meter Hub, rim or half shaft torque meter None Vehicle warm up 90 minutes at high-speed target speed before zeroing torque meters At least 30 minutes at 80 km/h Low-speed test Between 10 and 15 km/h From 35 km/h to 12 km/h High-speed test Between 85 and 95 km/h From 116 km/h to 93 km/h Torque drift Must not exceed 25 Nm N/A Anemometer calibration Run test for anemometer calibration misalignment No anemometer calibration for misalignment. Use of stationary weather station

Comparison of key points between US and EU air drag tests (2/2) Parameter EU constant speed US coastdown Tire rolling resistance (RRC) influence The RRC is assumed to be constant and the same at high and low speed The post-processing takes into account the speed dependence of the RRC Spin axle losses Torque measured at wheel, powertrain losses are irrelevant The spin axle losses are estimated using a quadratic regression on the tire rotational speed. CdA yaw angle correction Correction to zero yaw based on generic formula Correction to a yaw angle of 4.5° using CFD or wind tunnel testing Cross wind correction VECTO applies correction internally GEM does not perform any further crosswind correction

Comparison of the drag area determination procedures in the European Union and the United States ICCT is carried out air drag testing of EU and US vehicles over both testing procedures, constant speed and coast-down. Results indicate that the US coast-down test results in lower aerodynamic drag values, compared to the EU constant-speed test. Two upcoming papers, comparing the US and EU air drag testing methodologies, will be published in the first quarter of 2019

Takeaway messages VECTO and GEM show very good agreement when simulated over a large set of identical vehicles Results indicate that the US coast-down test results in lower aerodynamic drag values, compared to the EU constant-speed test The accurate simulation of CO2 emissions of HDVs is more dependent on the component input data than on the selected model (VECTO vs GEM). Harmonization of component certification benefits the implementation of future regulatory measures.

Harmonization possibilities for HDV CO2/FE certification

Overall conditions: Region specific adaptations necessary The CO2 certification methodology requires certain regions specific adaptations in the overall conditions (in blue). VECTO and GEM are physics based models that does not require major specific adaptations to be used by other regions. The component testing procedures developed by the EU are applicable to other regions without modifications. Fleet segmentation Duty cycles Payloads Standard bodies Testing procedure

Certified component performance data There are five key components that ne to measured to provide the necessary input for the simulation tool. The EU has in place a regulation that defines in detail the certification procedure for each of these components Transmission and driveline Aerodynamic drag Engine Tire rolling resistance Vehicle characteristics

Tire rolling resistance measurement In the US, the tire rolling resistance is measured using the test procedure defined by the standard ISO 28580. In the EU, the rolling resistance is measured according to UN/ECE R117. The provisions established in UN/ECE R117 are largely equivalent to those in ISO 28580. The determination of the rolling resistance can be done by measuring the horizontal reaction force, the torque input at the drum, the tire-drum system deceleration, or the power input at the drum. ISO 28580 / UN/ECE R117 include provisions for an inter-laboratory alignment procedure using a control tire, to allow direct comparison between different test rigs and methods.

Engine transient correction procedure in the EU Urban transient correction WHTC test COLD Urban, rural, motorway Rural transient correction WHTC test WARM Urban, rural, motorway Highway transient correction Engine mapping Fuel consumption full load and motoring Hot/cold balancing factor Fuel’s lower heating value Fuel correction factor Input data Dyno testing Correction Simulation Output data

Engine transient correction procedure in the US Phase 2 GEM cycle generator Minimum 24 engine cycles (3 vehicle cycles for 8 configurations) Minimum 8 standard vehicle configurations Engine testing: Cycle averaged map Engine mapping Fuel consumption full load and motoring Transient correction Input data Dyno testing Correction Simulation Output data

Measurement of transmission and axle losses In the EU, the measurement procedure of the torque losses of transmissions and axles is described in regulation EU 2017/2400, Annexes VI and VII. For transmissions and other torque transferring components, three measurement options are possible, with increasing degrees of complexity. In the US, the measurement of transmission and axles is an optional procedure. The default transmission and axle power maps are shown below. The measurement procedure of the power losses of transmissions and axles is described in §1037.565 and §1037.560 respectively.

Takeaway messages The US and EU component certification methodologies have several common points. Axles, tires, and engine mapping procedures are similar. Key differences include the aerodynamic drag determination methodology and the engine transient correction. Harmonization of component certification has many advantages: Facilitates transparent comparison of performance between different markets. Facilitates the implementation of future regulatory measures. Facilitates adapting GEM/VECTO to country-specific needs. Streamlined processes and reduced cost of compliance for international manufacturers.

Questions? Contact the HDV team at the ICCT