1. RDE testing of hybrid vehicles Contribution to the RDE working group
25 January 2016
European Commission - Joint Research Centre (JRC)
IET - Institute for Energy and Transport
Sustainable Transport Unit

2. Background RDE data evaluation verifies normality of test conditions
MAW (Appendix 5) and PB (Appendix 6): normality is evaluated by comparing work/power requirements of RDE driving vs. WLTP
Assumption: CO2 emissions are a reliable proxy of work/power
MAW (Appendix 5): MAW-average CO2 emissions [g/km] relative to WLTC characterization curve
PB (Appendix 6): binning of 3s moving averages of power at the wheels (measured or calculated instantaneous CO2 emissions)
CO2 approximates work/power of conventional ICE vehicles but may not be applicable to hybrid vehicles
Applying the current data evaluation may yield biased results or be infeasible for (plug-in) hybrid vehicles
3rd RDE package shall ensure applicability of RDE to hybrid vehicles

3. Background Problem for hybrid vehicles:
Part of the power is delivered by an electric engine that does not emit CO2
CO2 is thus not a reliable indicator of power output/engine work
Normality of driving = f(CO2; electric power)
Complex management of ICE vs. electric engine
Lab results not transferable to on-road driving
RDE test (1.5-2h) is longer than WLTC test
(Plug-in) hybrid vehicles may deplete battery and run on ICE mainly (drive range of plug-ins around 25 km)
CO2 emissions [g/km] are likely to be higher over an RDE trip than during type approval

4. Options “Hybrid” solution depending on the degree of hybridization
Exempting hybrid vehicles from RDE testing
RDE testing
Modified procedure
No modifications of the test procedure
Determining
CO2 emissions and electricity consumption
(Plug-in) hybrids may not be certifiable
Applying the current RDE data evaluation
Unequal treatment of ICE vs. hybrid vehicles
SOC (simple)
Current, voltage (advanced)
Abandoning RDE data evaluation for hybrid vehicles
Unequal treatment of ICE vs. hybrid vehicles
ΔSOC to CO2
Electric power to CO2
TA with Type 1 test in the lab
Adaptations and application of App. 5 and 6
“Hybrid” solution depending on the degree of hybridization

5. Contacts Pierre Bonnel pierre.bonnel@jrc.ec.europa.eu
Barouch Giechaskiel
Francesco Riccobono
Theodoros Vlachos
Martin Weiss:

6. Background – CO2 emissions
Determination of CO2 emissions:
Regulation 443/2009 – Regulations 715/2007 and 692/2008 – UNECE Regulation 101:
Annex 6: CO2 emissions of IEC vehicles [g/km]
Annex 7: energy consumption [Wh/km] and range [km] of electric vehicles
Annex 8: CO2 emissions of hybrid vehicles [g/km]
CO2 emissions of hybrid vehicles:
Not-externally chargeable: one NEDC test, control of energy status of the battery
Externally chargeable:
𝑀 𝐶𝑂2 = ( 𝑀 1 ∙𝑅𝑎𝑛𝑔𝑒+ 𝑀 2 ∙25𝑘𝑚) (𝑅𝑎𝑛𝑔𝑒+25 𝑘𝑚)
Reference to NEDC as test cycle
RDE makes reference to WLTP – GTR 15