1. RDE testing: how to define NTE emission limits?
Nikolaus STEININGER
Automotive Industries
European Commission, DG GROWTH
Brussels, 26 June 2015

2. Real Driving Emission (RDE) Testing of LDVs
Why? (short refresh)
How? (short refresh)
Where do we stand (1st & 2nd RDE package)?
[Next steps:
- RDE testing for PN: 3rd RDE package)
- In-service-conformity tests: 4th RDE package)]

3. RDE testing: why?
Massive air-quality problems: NO2 concentrations exceed regulatory limits mainly in urban hotspots
Main culprits: very high NOx emissions of LDVs exceeding regulatory emission limits by a factor 5+…
RDE emissions of Euro 3 – 5 vehicles more or less constant (demonstrated by many studies), despite nominal regulatory emission limits decreasing from 500 to 180 mg/km
Euro 6 vehicles peform slightly better but emit NOx still far above their emission limit of 80 mg/km. Huge differences between the performance of individual Euro 6 vehicles (ranging from "complying with reg. Euro 6 limits" to "not better than the worse Euro 5 vehicles"
Lab testing on a fixed test cycle is not sufficient for regulating NOx emissions!

4. RDE testing: why?
Euro 5/6 Regulation (EC) 715/2007 defines emission limits under "normal conditions of use", i.e. not in relation to a particular test cycle!
=> current test procedures fall short of legal requirements!
"Normal conditions of use" not explicitly defined in legislation
=> "normal is what actually occurs on the road"…
“Normal conditions of use”: collectivity of all driving situations an "emission vehicle type" encounters on the road weighted according to their statistical occurrence
=> regulatory emission limits =
average emissions on the road := "emission factors"
NB: average emissions on the road ≠ emissions at "average driving"

5. RDE testing: how?
Covering all “normal conditions of use" in one test impossible =>
Randomized test conditions potentially covering “all driving situations on the road"
Normalisation: achieve good statistical correlation of
"individual PEMS trip"  "normal conditions of use"
For all possible RDE tests performed according to legal requirements: Emissions < Not-To-Exceed (NTE) limits
NTE emission limit =
(regulatory emission limit) * (compliance factor)
=> CF > 1 accounts for variations of RDE test with respect to "normal conditions of use ", "benefit of doubt" for manufacturer
NB: In general NTE emission limit ≠ Emission factor

6. RDE testing: how?
Testing with on-board "portable emission measurement systems (PEMS)"
Randomized test cycles (dynamics & boundary conditions)
Simulation methods (???)

7. RDE: where do we stand?
Starting in 2011 a PEMS test procedure for RDE testing has been developed
"Normalisation" methods for dynamcial driving conditions (velocity, accelerations):
- Power binning method (CLEAR tool)
- Moving averaging windows method (EMROAD)
Set of ambient boundary and trip conditions
Technical procedures for performing the test
"PEMS test family" concept to limit amount of PEMS testing at initial type approval
For the moment emissions during cold start and after-treatment system regenerations are excluded from RDE assessment => to be addressed by special procedure in the future
=> RDE test procedure for initial type approval voted by TCMV on 19 May 2015

8. RDE: where do we stand?
As from January 2016: monitoring of RDE testing for NOx (no mandatory requirements yet)
As from September 2017/18 (new emission types/all new vehicles) : 1st step of NTE limits (NOx + PN)
As from … : 2nd step of NTE limits (NOx)

9. RDE: where do we stand?
Now: preparation of 2nd RDE package, to be adopted in 2015
“Complementary boundary conditions” addressing “biased driving” for a whole PEMS trip:
- Too dynamic/aggressive: limit 95%tile of v*a
- Too smooth: RPA = ∫v•a+dt /D > minimum value
NTE emission limits for NOx to be defined…

10. RDE: where do we stand? Mandatory NTE emission limits for NOx:
Values for the 2nd step to be defined via a strict interpretation of the existing regulatory Euro 6 emission limits (full redesign of vehicles possible)
Values for the 1st step (alternatives):
account for “the better end” of existing Euro 6 “standard” technologies (vehicles with NOx after-treatment) + “reasonably achievable” improvements (???) OR
"political" decision on the basis of 2nd step values + existing situation?

11. RDE: where do we stand?
Regulatory decision on 2nd step NTE emission limit not to be performed after the 1st step! Work for the two steps can be performed in parallel.
Time schedule:
Various technical elements needed: to be discussed today
Possibly two task forces
Presentation of a Commission service proposal for first discussion at TCMV in September
Intended vote at TCMV still in 2015

12. RDE: where do we stand? 2nd step NTE emission limit, process:
2nd step NTE emission limit, principles:
Uncertainties of measurement equipment, e.g. mass flow, pollutant concentrations, vehicle speed
Error propagation
Manufacturers' vs. regulator's risk
2nd step NTE emission limit, process:
Work by the JRC in progress
To be shared with stakeholders asap
Possibly task force?

13. RDE: where do we stand? Distribution of NOx emission performances
1st step NTE emission limit, technology route (brainstorming, approach not agreed yet by COM):
Consider "mainstream" Euro 6 vehicles, i.e. at least equipped with some NOx after-treatment
"Reasonable" short-term improvements, e.g. software re-calibration
Different vehicles + improvements =>
Distribution of NOx emission performances
NTE emission limits to be decided upon short-term air quality requirements + "acceptable" share of existing diesel vehicle models to be replaced on the market within 2 – 3 years

14. RDE: where do we stand?
1st step NTE emission limit, technology route, information needed:
Definition of "mainstream Euro 6 vehicle' (industry stakeholders, Euro 6 impact assessment?)
NOx emission performance distribution of existing "mainstream" Euro 6 vehicles => use PEMS data (?)
Quantitative short-term improvements, e.g. via software calibration changes (industry stakeholders?)
Time frame needed for developing this technology route …

15. Thank you for your attention!