WLTP Correlation measurement BMW, 18.09.2014 Christoph Lueginger WLTP Correlation measurement Analysis of 328iA xDrive Dekra-measurements

Analysis of Dekra measurements 328iA xDrive Agenda Introduction Applied corrections (RCB, road load). NEDC and WLTP measurement results. WLTP-NEDC delta. Check against the test procedure list. Missing points for the WLTP-NEDC delta. Additional results: 1-axle / 2-axle dyno influence of warm-up for chassis dyno setting. Summary. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Introduction Vehicle: BMW F34 328iA xDrive, 159 g/km. Following the SGS from 25.07.2014 at Munich Airport:  We propose using one representative measurement each (instead of using mean values).  We checked the measurements against the "test procedure checklist".  We show transparently the applied corrections. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Quickcheck results Calculation of times not understood (factor 1.03 / 1.015 should be applied, but factor 1 found). Influence on NEDC-WLTP-Delta assumed to be small, but for absolute value not negligible. If understood correctly, first run was used and only one run was performed. It is recommended to make 2-3 runs, and ignore the first run, as vehicle is not stable normally (to be equivalent to chassis dyno setting!). Quickcheck results between NEDC 2WD, NEDC 4WD and WLTP "NEDC" comparable, no correction needed. Quickcheck result of WLTP "High" shows relevant deviation to other tests. It is recommended to correct the WLTP "High" to get the right CO2-Delta between the cycles. CO2-influence of error in "High"-test: Approx. - 21 N  - 3.7 g/km  Correction + 3.7 g/km. -21N -21N -21N WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Road load setting on chassis dyno High Error Virtual High F0 confidential 19.76 F1 0.0677 F2 -0.00078 1 2 3 Deviation: - 3.6 g CO2 / km  Correction: + 3.6 g / km Road load delta High – NEDC. This would be also the expected chassis dyno setting delta. Delta of chassis dyno setting (abc-values) between High and NEDC (both based on WLTP warm up). Error due to chassis dyno setting also observed in quickcheck data. Recommended correction of WLTP High measurements of + 3.6 g/km (to be simulated by LAT as well). Recommended to use virtual F0F1F2 values as input, if "High"-measurements are used to compare or calibrate with simulation  see table. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Road load NEDC WLTP "Low" WLTP "High" WLTP "virtual High" Audi Tool WLTP "High" Audi Tool F0, F1, F2, TM confidential Delta CO2 [g/km] Basis 1.4 23.9 20.4 6.6 33.3 simulated by LAT 22.9 19.7 6.3 31.1 COMPAS by JRC 1.2 22.8 19.5 6.1 31.6 WLTP "Low" was measured with NEDC road load, which is reasonable to get e.g. the influence of warm-up or to separate road load from cycle influence. But WLTP "Low" is not equivalent to NEDC road load (e.g. payload factor, inertia classes). The provided WLTP road load values were calculated with BMW internal input parameters for that specific vehicle (similar to the Audi tool). Delta-CO2 is simulated in WLTP with this vehicle parameters, confirmed by LAT-simulation and JRC COMPAS model calculation. WLTP Correlation Measurements 328iA xDrive, BMW, 18.09.2014

Analysis of Dekra measurements 328iA xDrive Corrections cycle WLTP cold date 23.05. 2014 27.05. 2014 03.06. 2014 16.05. 2014 20.05. 2014 21.05. 2014 18.07. 2014 measured raw CO2-value [g/km] 167.6 165.7 166.7 185.2 186.6 186.1 186.2 road load NEDC High correction chassis dyno [g/km] + 3.6 RCB balance of battery [Ah] - 8.73 Ah - 7.62 Ah - 8.68 Ah - 9.07 Ah - 9.22 Ah - 9.20 Ah - 8.35 Ah RCB correction [g/km] + 4.5 + 3.9 + 4.7 + 4.3 corrected CO2-value [g/km] 172.1 169.6 171.1 193.4 195.0 194.4 194.1 road load "Low"/"High" [g/km] + 1.4 / +23.9 173.5 / 196.0 171.0 / 193.5 172.5 / 195.0 If temperature is considered to be representative enough for NEDC and WLTP, it is not corrected. No corrections for NEDC necessary. WLTP High to be corrected due to obviously wrong chassis dyno setting. Calculation of RCB correction:  according GTR Annex 6 -Appendix 2.  measurement of RCB: Details in backup. ΔCO2 = ΔRCB * U / 1000 * 1/alternatorefficiency * Willans * 1/distance WLTP from 3.6.2014: 8.68 Ah * 12 V / 1000 * (1/0.67) * 668 gCO2/kWh * (1/23.288 km) = 4.46 gCO2/km. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive NEDC measurements 06.06. and 28.05. appear to be outliers and are not considered in the average value. Proposed NEDC 2WD reference measurement, "Favorite": 12.06.2014: Justification: 12. and 13. are practically identical, 12. closer to correct engine temperature at start and closer to engine speed average. Proposed NEDC 4WD reference measurement, "Favorite": 04.06.2014: Justification: 15.05. and 04.06. are practically identical, no engine speed signal in 15.05. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive WLTP "Low" and "High" measurements With "High" RL-correction for wrong dyno setting, With "NEDC" RL-correction to High to be able to compare "NEDC" and "High" measurements. Proposed WLTP "NEDC" reference measurement, "Favorite": 03.06.2014: Justification: Close to the average and engine temperature close to desired value. Proposed WLTP "High" reference measurement, "Favorite": 21.05.2014: Justification: Close to the average and engine temperature close to desired value. Additionally engine speed signal only for 21.05. and 18.07. available. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive WLTP-NEDC Delta Dekra (corrected): ΔCO2 High-NEDC 26.4 g/km (26.2 – 27.0 g/km) BMW (corrected): ΔCO2 High-NEDC 26.1 g/km CO2 [g/km] WLTP High ΔHigh-NEDC NEDC Measured CO2-delta is only valid, as long as the proposed corrections are applied (RCB, road load)! Recommended to take delta of single measurements ("Favorites") where the smallest corrections are applied (from WLTP High measurements)  26.4 g/km. This is not the final delta, as some points from the testprocedure list are missing! WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Deviation (Y/N/value) Analysis of Dekra measurements 328iA xDrive Test procedure checklist No. Subject NEDC Deviation (Y/N/value) WLTP Delta [g CO2 / km] Notes   Measured values 12.06.2014, corrected 168.0 21.05.2014, corrected 194.4 26.4 Single , representative measurement Version of roadload calculator (V1 or V2) Tyre tread depth: 50-90% - Tyre tread depth: 80-100% if V1: declaration of delta_RR + Interpolation OR F0-Change if V2: no changes N 0.8 from Audi-Tool: 6 N ==> extimated with 0.8 g/km CO2 1 soak temperature 25°C set point ± 3°C 23°C set point ± 3°C 2 oil and coolant temperature at start of the measurement ± 2°C to soak temperature small 23°C ± 2°C 3 test temperature 23 °C ± 3 °C 4 test mass Mass in running order + 25 kg (OEM data) TMH (additionally TML (instead of TML also NEDC-inertia-class may be used)) if NEDC-inertia class was used for Low -> add CO2 for payload-mass and stepless inertia same interpolation formula as in CO2-interpolation can be used 5 inertia Stepwise inertia class at NEDC test mass. Step-less approach: inertia mass = test mass. Test @ TML and TMH Important: Measurement AND simulation in NEDC should use inertia class as inertia, as this is the physical impact on CO2 (not kerb mass + 100kg). 6 aerodynamics aerodynamics as type approval car (resulting from weight, tyre-choice, no other options) "High" / worst-case (for some cars also "Low" should be measured) 7 rolling resistance RR resulting from widest tyre "High": worst RR-class (for some cars also "Low" should be measured) 8 cold start Yes 13 Dynamometer road load setting NEDC and R83 tolerances WLTP GTR with tolerances of the GTR How to consider if not measured? (Annette) 14 Dynamometer road load: inertia of rotating parts Always 0% +1.5% of (Miro+25kg) single axle, 0% twin axle. not relevant (2-axle dyno!) Single axle dyno is treated differently on NEDC by 1.5%. Road load issues always use 3%. 15 4WD vehicles 1-axle dyno allowed 2-axle dyno mandatory effect on Road Load hopefully taken care of in f0,f1,f2; effect on dyno setting in WLTP (2nd axle warm); effect on increased cold-friction on 2nd axle 16 Rechargable Energy Storage System (RESS) Legislation does not require monitoring or correction. Monitored and the delta energy balance is taken into account for fuel consumption Battery fully charged overnight. On both test cycles the RCB must be monitored. 18 gear shift strategy Fixed speed not relevant Obtained from engine speed and power curve of the vehicle, GSI for MT-hybrids with the Gear Shift tool provided by Heinz Steven. 22 DPF regeneration As prescribed in R83 As prescribed in GTR 31 RLD procedures NEDC warm-up RLD Calculation (average of times) WLTP warm-up (procedure differences to NEDC) RLD calculation difference (harmonic average of times) Y open F0F1F2 for High only calculated as delta, procedure difference not included, e.g. averaging of force vs. times in NEDC. Determination only with coast down testing. 33 RLD vehicle chracteristics OEMs to provide data Vehicle characteristics differences: mass, aero-drag, tyre rolling resistance (incl. tyre tread depth, RR-classes instead of tyre-width). If this cannot be measured, solution see "RLD procedures". 34 optional equipment weighted average needed for weight, RR, aerodynamics. To be provided by OEMs 35 CO2 correction with Europe average temperature as new EU regulation Necessary in order to correlate with all test elements which are planned to enter for EU. Applicable in (EU) WLTP: [14°C] setpoint and time [9h] not decided yet. 36 Normalisation corrections open, not defined yet CO2 family tolerance up to 4% Final NEDC->WLTP Delta 27.2 [g CO2/km] WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Missing points in measured delta corrected measurement not included in measurement and additionally open points CO2 [g/km] issue incl.? road load "High" Y warm-up WLTC check list executed ? WLTP High Delta CO2 27.2 + X g/km ? GTR updates phase 1b, EU WLTP deviations new ? ? family tolerance type approval up to 4%. EU WLTP issue normalization new 0.8 + X? ATCT 14°C point. 35 TP-list coast down process, e.g. tire thread depth or calculation error point 31-33 TP-list 1.5% rot. masses  not relevant, 2-axle dyno point 14 TP-list Dekra, corrected measurement: + 26.4 g/km All road load issues are covered, if OEM WLTP type approval values are used in a meta model. NEDC Many of the agreed points are already included in the corrected measurement delta. The calculated delta of approx. 27 g/km also does not include all issues. Final delta cannot be determined without final GTR / EU WLTP and additional measurements. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Influence of 1-axle / 2-axle dyno mode Result of 2.5 g/km matches BMW experience. The measured CO2-delta may be dependent on 4WD technology and therefore OEM dependent. This delta cannot be simulated and has to be added additionally in the correlation meta model. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Influence of warm-up cycle for chassis dyno Derived from abc-values of NEDC and WLTP "NEDC". Possibly wrong as WLTP High chassis dyno setting was not correct  effect should not be based on this measurement only. Clear influence on abc-values visible, as WLTP leads to warmer conditions and therefore a higher chassis dyno load. Effect is between 15-30 N (velocity dependent), at small speeds most likely disturbed by measurement tolerances.  Proposed influence: 15-20 N (2-3 g CO2 / km). This delta cannot be simulated and has to be added additionally in the correlation meta model. WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Summary Chassis dyno setting wrong for WLTP "High", but can be corrected. Some small signal-errors (e.g. battery current). From the measurements we gain the following main results: The corrections should be crosschecked (e.g. CO2-effect by road load already checked by JRC and LAT, also RCB correction to be checked). From now on only "Favorite" measurements are used (same delta but better as simulation input and easier to discuss) For WLTP High calibration simulation use "virtual High" road load to compensate the wrong chassis dyno setting. Results 328xiA High corrected measurement additional points final Influence of warm up WLTC instead of NEDC Influence of 2-axle dyno instead of 1-axle dyno Delta CO2 [g/km] 26.4 27.2 ? 2-3 2.5 WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

Analysis of Dekra measurements 328iA xDrive Backup WLTP Correlation Measurements 328iA xDrive, BMW, 31.07.2014

WLTP GTR Rotating Masses Clarification for road load inertia setting 1-axle: m + mr (1.5%) 2-axle: m  on road on dyno  Coast down times measured Calculation times to forces Road load F0F1F2 Calculation forces to times Chassis dyno setting Road load Vehicle speed m + mr (3%) m + mr (3%) to be consistent same mass to be used If "3%" is mentioned in this presentation, it includes also individually determined values. The 3% are used to consider rotating masses. Only wheels are relevant, drivetrain influence is very small compared to the wheels. To get the same times measured at the coast down the same mass has to be used in both calculations and is therefore independent of 2WD/4WD or 1-axle/2-axle dyno mode… Note: mr always refers to "Miro + 25kg", not to TM! WLTP Rotating Masses, BMW, 20.05.2014

WLTP GTR Rotating Masses Clarification for dyno setting 2-axle dyno 1-axle dyno + 1.5 % of (Miro+25kg) for not driven axle inertia setting: TM inertia setting: TM + 1.5% * (Miro + 25kg) In case of a 1-axle dyno, the effect of the non-rotating axle has to be compensated by the additional mass of 1.5% * (Miro + 25kg). The 3 % / 1.5 % regarding inertia are the same values as used for calculating the road load, but for a complete different reason. Therefore these two issues should not be mixed up. (Miro = mass in running order) WLTP Rotating Masses, BMW, 20.05.2014