1. – EU WLTP
Supplemental Test for Determination of CO2 Emissions under Regional Conditions
Rob Gardner, TRL and Andreas Eder, BMW
for the Working Group on the Development of the Supplemental Test

2. Supplemental Test Subgroup for development of test procedure:
Rob Gardner, TRL
Klaus Steininger, COM
Stephan Redmann , BMVI Germany
Helge Schmidt, TÜV Nord
Iddo Riemersma, T&E
Markus Bergmann, Audi
Christophe Griard, PSA
Andreas Eder, BMW
Motivation of the Supplemental Test:
To reflect the CO2 values obtained in real life EU-COM wants to introduce an additional test under „realistic conditions“ .
The conditions for Europe agreed in LabProcICE are based on the analysis for eco innovations by JRC.
The Type-1 test at 23 °C shall be performed for all combined approach families during type approval
The Supplemental Test shall be performed only once for a temperature correction vehicle family

3. Supplemental Test - Concept
Vehicle family
Test cell, soak: 23 °C
Soak time: 6 – 36 h
Engine oil, water: 23 °C
CO2_3
CO2_1
CO2_2
Supplemental test
Test cell, soak: 14 °C
Soak time: 9 h, Tolerance h
Engine oil, water: no restrictions
FCF = family correction factor
CO2_ind = individual CO2 value
Creg = regional conditions

4. Supplemental Test – Agreed Procedure
Preconditioning same for Type 1, at the request of manufacturer also at 14°C possible.
Road load and dyno settings as specified in Sub-Annex 4.
From the Supplemental Test Vehicle Family, the CO2 Vehicle Family with the lowest engine capacity shall be selected, and the test vehicle shall be in the ‘vehicle High’ configuration of this family.
All transfers (e.g. from pre-con to soak, soak to test, etc. ) shall be performed as quickly as possible, with a maximum delay of 10 min.
Emission test as specified in Sub Annex 5, but at 14°C.

5. supplemental test Family (STF) Definition
Unless vehicles are identical with respect to all the following characteristics, they shall not be considered to be part of the same supplemental test family:
Powertrain architecture (i.e. internal combustion, hybrid, or electric);
Combustion process (i.e. two stroke, four stroke, or rotary);
Number and arrangement of cylinders;
Method of engine combustion (i.e. indirect or direct injection);
Type of cooling system (i.e. air, water, or oil);
Method of aspiration (i.e. naturally aspirated, or charged);
Fuel for which the engine is designed (i.e. petrol, diesel, NG, LPG, etc.);
Whether or not a heat storage device is installed;
Catalytic converter (i.e. three-way catalyst, lean NOx trap, SCR, lean NOx
catalyst or other(s));
Whether or not a particulate trap is installed; and
Exhaust gas recirculation (with or without, cooled or non-cooled).
In addition the vehicles shall be similar with respect to the following characteristics:
The vehicles shall have a variation in engine cylinder capacity of no more
than 20% of the vehicle with the lowest capacity; and
Engine compartment insulation shall be of similar type [TBD]

6. Supplemental Test – Family – Part2
Supplemental information family concept: T
Vehicle 1 in family T
Vehicle 2 in family
T_CD_1
T_soak_1
T_CD_2
T_soak_2 …
1/3 Δt
1/3 Δt
ΔT_2
ΔT_1
26°C
23°C
20°C
26°C
23°C
20°C
t_soak
t_soak
= average soak area temperature of last third of the soak time
 All the ΔT_i values within a family have to be in a tolerance of [5]K [TBD]

7. BMW - Soaking Test facilities
14°C cool down tests in climate test facility
 soaking in big volume with both vehicles one to another during cool down 1
328xi
320iA 2
23°C cool down tests in regular soak area

8. Engine coolant temperature @14°C, 9h Engine coolant temperature
BMW - Cool down and FCF Values
Vehicle
Engine coolant 9h
Engine coolant temperature
@23°C, 9h
Test1
Test2
328xi Limo (MT)
T_amb+9.1
T_amb+8.5
T_amb+8.8
T_amb+6.4
320iA GT (AT)
T_amb+8.6
T_amb+7.3
T_amb+5.7
ΔT=0.6K
ΔT=3.1K 1 2
Vehicle
FCF
Test1
Test2
328xi Limo (MT)
1.018
1.015
320iA GT (AT)
1.020
1.014
BMW /PSA proposal [5K] absolute temperature tolerance due to restrictions of soak
areas.

9. Summary Supplemental Test drafted and ~80% completed.
Major open points:
Quantitative criterion for insulation within engine compartment.
Tolerance for temperatures after cool down for family check.
Tolerances for heat storage devices.
Text for handling of Plug-in vehicles.

10. Backup

11. Engine Media Temperature after Pretest

12. Supplemental Test parking Time Different approaches
Basis is parking time distribution from Eco Innovations (JRC).
Current approach:
Typical use cases for soak time are overnight parking ~10-12h and daytime parking at work ~8h. This leads to tpark= 9h.
Alternative approach:
Neglect extremes: - Parking events shorter 1h are mostly related to short stops and short trips (next slide)  always engine warm start  representation by one WLTP ok.
- Parking events longer than 24h – not representative for daily driving conditions
Take the median: Resulting parking time is 8h

13. ATCT for PHEVs in WLTP. ATCT impact on the electric range of CD test.
Type I
@ 23°C
charging
@ 14°C / 9h
ATCT
@ 14°C
-3% eRange
UF [%]
Electric Range [km] 10 30 20 40 50 60 70 80 90
100
Example PHEV
(40km eRange, 100g CO2/km)
40 km electric range +
Shift in UF curve
ΔCO2 ≤ 1 g/km
For i3 Range Extender, the influence
would be <<1g/km CO2
Proposal:
Correction of Charge Sustaining according to ICE procedure
No correction of Charge Depleting Test, e-Range, and UF.

14. Tolerances for Heat storage in ATCT
Definition in ATCT Proposal:
If active heat storage systems are installed, the heat capacity and the time for heat release within the family has to be comparable as follows: the heat capacity is defined by the enthalpy stored in the system and has to be within a range of [10]% for a vehicle family. The time for heat release at engine start within a family has to be in a range [10]%.
Maximum engine warm-up CO2-potential
Engine hardware, media (oil, water) and exhaust control system completely heated:
 in NEDC ≈ 8%
 in WLTP ≈ 5%.
Maximum Heat Storage Systems CO2-potential
Only heat up of engine media (oil, water):
 in NEDC ≈ 3%
 in WLTP ≈ 2%.
Maximum CO2-inaccuracy due to Heat Storage capacity tolerance of [10%]
 in WLTP ≈ 0.2%.