Ref. Ares(2019)2889071 - 30/04/2019
Background and disclaimer
To support the Member States market surveillance activities regarding emissions of light-duty
vehicles, the European Commission has published a Guidance note1 (hereinafter "the Guidance")
to evaluate emissions strategies and to detect the presence of defeat devices. The JRC contributed
to the development of the Guidance and provided a testing protocol which the responsible
authorities may use to detect illegal Auxiliary Emissions Strategies (AES). The protocol includes
three main elements:
- It defines the principles to test vehicles, i.e. to modify certain elements of the standard
emissions tests and to assess whether these modifications are likely to influence the behavior of
the emissions control technologies;
- It proposes NOx emissions thresholds for different categories of tests, not with the objective to
verify the vehicle compliance but rather to point at suspicious results which might be caused by
illegal strategies;
- The Guidance goes further by introducing acceptable and non-acceptable AESs for specific
emissions control technologies.
The Guidance was published in January 2017 and is subject to continuous improvements from
the lessons learned during the National surveillance programs and the JRC testing. The JRC
keeps testing vehicles with the objective to improve the test protocol, in particular its application
to a variety of technologies and emissions standards.
The present document is an application of the protocol to a specific vehicle, which might have
been tested in one or several European National programs. The JRC results and the information
contained herein might be subject to analysis and verification by the responsible authorities. If
the vehicle has not been tested in a national program and is found to exhibit anomalous results,
the responsible authority shall repeat the tests on a similar vehicle to eliminate the potential
uncertainty or the bias inferred from the single vehicle tested at the JRC.
Whenever possible, the report provides detailed information (e.g. functioning of the emissions
control technologies and/or second-by-second data) to provide explanations regarding the
difference(s) which may appear between the emissions from tests conducted under different
conditions.
As the declarations regarding the functioning of the emissions control are under the control of the
vehicle Type Approval Authority, the report does not provide any judgement on the legality of
the observed AES. The vehicle emission performance is only confronted with the Guidance.
1 Commission Notice of 26.1.2017 - Guidance on the evaluation of Auxiliary Emission Strategies and the
presence of Defeat Devices
2
Acronyms and abbreviations
AES: Auxiliary Emissions Strategies
CF: Conformity Factor
DOC: Diesel Oxidation Catalyst
DPF: Diesel Particulate Filter
ECE: Economic Commission for Europe
ECS: Emissions Control Systems
ECU: Engine Control Unit
EGR: Exhaust Gas Recirculation
EUDC: Extra-Urban Driving Cycle
JRC: Joint Research Centre
LNT: Lean NOx Trap
MAW: Moving Average Window
NEDC: New European Driving Cycle
OEM: Original Equipment Manufacturer
RDE: Real Driving Emissions
RL: Road Load
RT: Recommended Threshold
SCR: Selective Catalytic Reduction
WLTC: Worldwide harmonized Light vehicles Test Cycle
WLTP: Worldwide harmonized Light vehicles Test Procedures
3
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Test program overview
The application of the protocol to detect illegal AES is subject to adaptations depending on the
vehicle technologies.
Table 1 shows the types of tests and their objectives for the vehicle
presented in this document.
Table 1: Type of tests and objectives
Type of Test
Category2
Objectives
NEDC Cold
-
Vehicle emissions compliance under standard conditions
NEDC Hot
2
Emissions performance with hot engine
Potential timer or hot vehicle condition triggering AES
NEDC w/o
2
Emissions performance on a cold started NEDC driving cycle without
preconditioning Cold
pre-conditioning of the vehicle, to check for the presence of a defeat
device triggered by the vehicle conditioning
NEDC after grade Hot
2
Emissions performance on a hot started NEDC driving cycle after
jacking up the car front, to check for the presence of a defeat device
triggered by the vehicle inclination
NEDC +10% Cold
2
Vehicle emissions on a modified NEDC driving cycle driven with 10%
higher speed, to check for the presence of a defeat device triggered by the
driven distance
NEDC + Load Hot
2
Emissions performance with hot engine and additional engine loads (A/C
and lights)
Potential use of vehicle systems triggering AES
NEDC +10°C Cold
2
Emissions performance at low ambient temperature
Temperature condition potentially triggering AES
NEDC +30°C Cold
2
Emissions performance at high ambient temperature
Temperature condition potentially triggering AES
WLTC Cold
3
Emissions performance on WLTC
Functioning of the ECS under controlled conditions beyond the NEDC
duration and distance (22 minutes)
WLTC Hot
3
Emissions performance on WLTC
Effect of hot engine and functioning of the ECS under controlled
conditions beyond the NEDC duration and distance (22 minutes)
RDE
3
Emissions performance on road
Functioning of the ECS under uncontrolled conditions and beyond the
NEDC duration and distance (22 minutes)
2 The categorization of the various types of tests is made by the responsible testing entity and should be
based on the lessons learned from its own testing activities and/or the publicly available information. It
is subject to adaptations and revisions depending on the emissions control technology.
4
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Main results
Table 2 shows the main emissions findings when applying the test protocol to the vehicle.
Table 2: Tailpipe emissions performance
Type of test [Category]
Remarks
Comp.3 or CF4
NEDC cold
The vehicle is compliant for all pollutant emissions
Compliance OK
NEDC Hot [2]
The average CF for the NOx emissions over hot NEDC cycles is CF Not OK
1.8
RTNOx =
1.5
Under these conditions, the average NOx emissions were higher
CFNOx =
1.8
when compared to the values obtained over a standard cold
NEDC by a factor of ca. 3. This could be attributed to the lower
EGR rates (See Figure 1)
NEDC w/o preconditioning
The average CF for the NOx emissions over cold NEDC cycles is OK
Cold [2]
0.8
RTNOx =
1.5
CFNOx =
0.8
NEDC after grade Hot [2]
The average CF for the NOx emissions over hot NEDC cycles is CF Not OK
1.6
RTNOx =
1.5
Under these conditions, the average NOx emissions were
CFNOx =
1.6
comparable to those observed over the hot NEDC.
NEDC +10% Cold [2]
The average CF for the NOx emissions modified cold NEDC
OK
cycles (+10% speed) is
1.1
RTNOx =
1.5
CFNOx =
1.1
NEDC + Load Hot [2]
The average CF for the NOx emissions over hot NEDC cycle
OK
with additional engine load (A/C and lights on) is
1.4
RTNOx =
1.5
CFNOx =
1.4
NEDC +10°C Cold [2]
The average CF for the NOx emissions over cold NEDC cycles at
CF Not OK
10°C is
2.4
RTNOx =
1.5
Under these conditions, the average NOx emissions were higher
CFNOx =
2.4
when compared to the values obtained over a standard cold
NEDC (at +23°C) by a factor of ca. 4. This could be attributed to
the EGR valve functioning.
NEDC +30°C Cold [2]
The average CF for the NOx emissions over cold NEDC cycles at
CF Not OK
30°C is
1.7
RTNOx =
1.5
Under these conditions, the average NOx emissions were higher
CFNOx =
1.7
compared to the values obtained over a standard cold NEDC (at
+23°C) by a factor of ca. 3. This could be attributed to the lower
EGR rates (See Figure 1).
WLTC Cold [3]
The average CF for the NOx emissions over cold WLTC cycle is OK
1.9
RTNOx =
5
CFNOx =
1.9
WLTC Hot [3]
The average CF for the NOx emissions over hot WLTC cycle is OK
2.4
RTNOx =
5
CFNOx =
2.4
RDE [3]
The CF for the NOx emissions over RDE routes varies between
OK
3.6 and
3.8
RTNOx =
5
min. CFNOx =
3.6
max. CFNOx =
3.8
3 Compliance (Comp.) on Type 1 test versus the applicable limits
4 NOx Conformity Factor (CF) versus the thresholds recommended in the Guidance. CFs exceeding the
thresholds are indicative but may point at problematic emissions strategies
5
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Additional information regarding the AES
Over the hot start NEDC driving cycles (types of test NEDC Hot and NEDC after grade Hot),
and over the test conducted with +10°C and +30°C driving ambient temperature, this vehicle
exhibited NOx emissions above the thresholds recommended in the Guidance.
Figure 1 shows the cumulative EGR usage over these tests together with the EGR usage over the
cold started NEDC (shown in red).
For the cold start tests performed at +10°C and +30°C (Figure 1 - left panels), the cumulative
NOx emissions was 4 and 3 times higher than those obtained at 23°C under standard condition
(cf. Cumulative NOx in g). This difference can be explained by the lower usage of the EGR valve
(cf. Cumul. EGR), with a decrease of 35% and 20% at +10°C and +30°C respectively compared
to the tests done at +23°C.
For the hot start tests (NEDC Hot and NEDC after grade Hot, Figure 1 – right panels), the
cumulative NOx emissions was ca. 3 times higher than those obtained over the cold started
NEDC at 23°. This difference can also be explained by the lower usage of the EGR valve, with a
decrease of 35% compared to the cold started NEDC done at +23°C.
Figure 1: NOx emission (first row), NOx cumulative emission (second row), cumulative EGR
(third row) and velocity (fourth row) of the vehicle over the cold started (left column) and hot
started (right column) NEDC tests.
6
Appendix - Vehicle Report - Anonymized Vehicle
[XX001]
November 22, 2017
A. Vehicle details
Table 1: Vehicle specification. RL stands for road load, with Inertia,
F0, F1 and F2 in kg, N, N/(km/h) and N/(km/h)2 respectively.
NA stands for not available (vehicle covers by a non-disclosure
agreement).
Vehicle OEM:
NA
Vehicle Model:
NA
Vehicle Class:
M1
Vehicle Code:
XX001
Fuel Type:
Diesel
Injection:
Common Rail
Emissions Control Technologies:
DOC+EGR+SCR+DPF
Model Year:
2017
Vehicle Identification Number:
NA
Homologation Number
NA
Emissions Standard:
Euro6b
Odometer Reading:
6479
Transmission Type:
Automatic
Number of Gears:
8
Engine Capacity in cm3:
2967
Rated Power in kW:
193
Tyre Dimensions:
NA
RL coefficients NEDC
Inertia: 2270, F0: 134.5, F1: 0.36, F2: 0.056
RL coefficients WLTC
Inertia: 2390, F0: 194, F1: 0.37, F2: 0.059
Declared CO2 value in g/km:
179
1
B. Tests conducted
Table 2: Laboratory tests conducted
Type
Repeats
Category of procedure
Standard NEDC acc. ECE R83
3
Reproducing the Type 1 test
NEDC - Hot vehicle
2
Category 2
NEDC w/o conditioning - Cold vehicle (+4h)
2
Category 2
NEDC after applying grade - Hot vehicle
2
Category 2
NEDC with +10% speed - Cold vehicle (+4h)
2
Category 2
NEDC with load (A/C) - Hot vehicle
2
Category 2
NEDC @ +10°C - Cold vehicle (+4h)
2
Category 2
NEDC @ +30°C - Cold vehicle (+4h)
2
Category 2
WLTC - Cold vehicle
2
Category 3
WLTC - Hot vehicle
2
Category 3
Table 3: On-road tests conducted
Type
Repeats Category of procedure
RDE Route 1 (Esperia)
2
Category 3
RDE Route 2 (Labiena)
2
Category 3
Categories of procedure included in Tables 2 and 3 are those proposed in the Commission Guidance
(Commission Notice of 26.1.2017 - Guidance on the evaluation of Auxiliary Emission Strategies and the
presence of Defeat Devices).
Generic test protocol: Version 10/08/2016
Application by the JRC: Version 10/08/2016
2
C. Laboratory Emissions Results
• Average results for the repeated tests
Table 4: Average laboratory emissions.
Type
NOx [mg/km] THC [mg/km] CO [mg/km] CO2 [g/km] PN [E+9/km]
NEDC Cold
47.1
14.8
156
202
10.4
NEDC Hot
146
3
20.4
185
28
NEDC w/o preconditioning Cold
61.7
14
130
203
70
NEDC after grade Hot
128
3.3
20.7
189
49.5
NEDC +10% Cold
89.8
11.2
144
218
18
NEDC + Load Hot
114
3.4
7
213
61.2
NEDC +10°C Cold
194
12.1
155
217
23
NEDC +30°C Cold
134
9.9
157
194
13.1
WLTC Cold
155
4.6
155
222
26.7
WLTC Hot
196
1.2
62.6
216
55.2
3