1. GTR proposal for Roadload determination JAPAN June 2015 WLTP-11-13e

2. Background There will be a chance for roadload to deviate from the real vehicle performance due to many possible ways to determine the roadload with tolerances. Intentional abuse of tolerance has to be avoided. For example, wind tunnel may have the correction factor(s) which is outside of GTR restriction. On the other hand, as wind tunnel or flat belt, etc. can improve repeatability/accuracy and reduce testing burden significantly. It should be allow to use these technique(i.e. wind tunnel etc.), however the manufacturer should be responsible for the outcome of a mass production car. Since ISC/COP should not be going to GTR at this phase1b timing, the proposed wording was selected with care. A reference method was hard to determined and should be discussed in Phase2. 2

3. Proposal 3 Annex 4. 3. Measurement criteria 3.1. Required overall measurement accuracy. The manufacturer shall be responsible for the accuracy of the road load specification and will ensure this for each production vehicle within the road load family. Tolerances within the allowed road load determination, simulation and calculation methods should not be used to underestimate the road load of production vehicles. At the request of the responsible authority the accuracy of the road load specification of an individual vehicle shall be demonstrated. 3.1.1. Required overall measurement accuracy for each parameters. The required overall measurement accuracy shall be as follows: (a)Vehicle speed: ± 0.5 km/h or ± 1 per cent, whichever is greater; ….. Justification To prevent the tolerances for roadload deamination from abuse and to clarify the manufacturer’s risk.

4. Compliance check system 4 R/L determination Type approvalISCCOP CO2 value R/L value Emissions Never disclosed Never checked with production car. Roadload values have been used in type approval tests without checked with production car or disclosed to public, even though the values are very critical for the tests.

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6. H L CO2 family A: Diesel A AT Highest cycle energy R/L: Test with WT+FB CO2: Test R/L: Level 1 Interpolation CO2: Test Ind R/L: Level 2 Interpolation CO2: Interpolation H L CO2 family C: Gasoline C AT Lowest cycle energy R/L: Test with WT+FB CO2: Test Ind R/L: Level 2 Interpolation CO2: Interpolation R/L: Level 1 Interpolation CO2: Test H L CO2 family B: Diesel B AT Ind R/L: Level 2 Interpolation CO2: Interpolation R/L: Level 1 Interpolation CO2: Test R/L: Level 1 Interpolation CO2: Test Roadload family A by Road load interpolation under roadload family rule: H +/- 5%±ε Coastdown Test for H Allowable roadload range for WT+FB method R/L Determination for L Coastdown Test for L Option A: CoastDown test Option B: WindTunnel+Flatbelt R/L Determination for HL Ind 0 L L R/L H H +/- 0.015m 2 ±ε +/- 5%±ε Option A: Wind tunnel test Option B: Simulation H H L L Max. 35% cycle energy difference ε is added because 5% is only required when its validation testing. Link of Interpolation among R/L family

7. 7 High Repeatability Less Testing burden/cost Technology development Wind tunnel, Flatbelt, dynamometer, Simulation, etc. Coast down test (golden standard method) Level playing field General standardized test method Transparency

8. Roadload determination method 1.Measure roadload by testing. a)Coast down with anemometer b)Coast down without anemometer c)Torque meter d)Alternative method Aerodynamics –Wind tunnel –Alternative method (e.g. CFD simulation) Mechanical loss –Flat belt –Chassis dynamometer 2.Calculation based on actual measurement test described above. a)Combined approach b)Roadload interpolation under Roadload family rule c)Hybrid approach (combined default approach) 3.Default Roadload. 8 Many possible ways to determined a roadload.

9. Tolerance/restriction/accuracy 9 35% 0.015m2 5% 2% overall accuracy for each vehicle roadload is not clear.