Worldwide harmonized Light
vehicles Test Procedures
What is WLTP and
how does it differ from NEDC ?
Pascal Mast 25.06.2014
Business Line Manager Emission
Agenda
TÜV SÜD Auto Service GmbH
14-06-13
1
History
2
Process
3
Comparison WLTP / NEDC
4
Conclusion
Slide 2
History
Objective
In march 2014, the proposed WLTP GTR was approved and adopted by the following countries:
Europe, Australia, China, India, Japan, Norway, Republic of Korea, Moldavia, Russia, South
Africa and Turkey.
The UN Global Technical Regulation (GTR) aims at providing a worldwide harmonized test procedure
to determine in a repeatable and reproducible manner :
•
•
•
•
•
•
Exhaust gases concentration
Particulate Mass and Particle Number
CO2 emissions
Fuel Consumption
Electric energy consumption
Electric range
It is for the moment limited for light-duty vehicles and will provide the basis for the regulation of
regional type approval and certification procedures.
TÜV SÜD Auto Service GmbH
14-06-13
Slide 3
History
Initial road map
In November 2007, the UNECE World Forum for Harmonization of Vehicle Regulations (WP.29)
decided to set up an informal group under GRPE to prepare a road map for the development of the
WLTP.
GRPE presented in June 2009 a first road map consisting of 3 phases:
• Phase 1 (2009–2014): Development of the driving cycle (WLTC) and test procedure (WLTP)
• Phase 2 (2014–2018): Low temp./high altitude test procedure, durability, in-service conformity,
on-board diagnostics (OBD), mobile air-conditioning (MAC) system efficiency, off-cycle / real
driving emissions
• Phase 3 (2018-…): Emission limit values and OBD threshold limits, definition of reference
fuels, comparison with regional requirements.
TÜV SÜD Auto Service GmbH
14-06-13
Slide 4
History
Planned benefits:
The planned benefits of implementing WLTP are:
• Better real driving conditions
• Better implementation of CO2 efficient engine technologies
(≠ calibration based on NEDC)
• On a global scale:
 Cost reduction for OEMs
 Unified vehicle design
 Simplified administrative procedures
TÜV SÜD Auto Service GmbH
14-06-13
Slide 5
Outline
TÜV SÜD Auto Service GmbH
14-06-13
1
History
2
Process
3
Comparison WLTP / NEDC
4
Conclusion
Slide 6
Process
Vehicle class
Class 1
Vehicle classification
• Low power vehicles
• Based on the Power / Unladen mass
ratio (W/kg)
• Each class has it’s own cycle
• Maximum laden mass ≤ 3,500 kg
• Downscaling procedure for vehicle with
insufficient power
• PWr ≤ 22 W/kg
• 3 Phases: Low1 + Medium1 + Low1
Class 2
• 22 W/kg < PWr ≤ 34 W/kg
• 4 Phases: Low2 + Medium2 + High2 + Extra-High2
Class 3
• 2 Subclasses: Vmax>120 km/h and Vmax<120 km/h
• PWr > 34 W/kg (Most EU cars)
• 4 Phases: Low3 + Medium3x + High3x + Extra-High3
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14-06-13
Slide 7
Process
Cycle
Version 5.3 has been selected as the official version
140
Speed [km/h]
120
Phase 1
Phase 2
Version 1
Phase 3
100
Version 2
80
Version 3
Version 4
60
Version 5.3
Phase 4
40
20
0
0
•
•
•
•
200
400
600
800 time [s] 1000
1200
1400
1600
1800
Total cycle time: 30 min
Distance: 23,26 km
Max. speed: 131,3 km/h
Avg. speed with stops: 46,5 km/h
TÜV SÜD Auto Service GmbH
14-06-13
Slide 8
Process
Procedure
Dyno settings
Test conditions
Cycle
Formulas
140
120
100
80
60
40
20
0
0
• New specific Test
Mass definition:
TM = Curb Weight
(incl. driver) +
Optional Equipt. + 25
+ 0,15* (LM - CW OE - 25)
 Impact on FC ?
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• Soak area: 23°C ±3°C
• Soak time:
6 h ≤ t ≤ 36 h until oil,
coolant ± 2°C target
• Force cooling allowed
• Test cell: 23°C ± 5°C
5,5 ≤ Ha ≤ 12,2 (g/kg)
14-06-13
500
1000
1500
• WLTC as
preconditioning cycle
• More WLTC possible
if needed to stabilize
• Speed tol.: ± 2 km/h
<1s less than 10 times
• Fuel Consumption,
Dilution Factor,
Mass of each gas,...
 formulas same
as EU (4,5,6)
Slide 9
Process
Gear point selection for manual cars
Required datas
• Prated : max rated power
• s : engine speed @ Prated
• Nidle : idling speed
• TM (mass) + f0,f1,f2 (driving resistance)
• Ndvi : engine speed to car speed ratio for
each gear  need: gear transmission ratios,
dynamic radius of tire, final reduct° ratio
• Full load power curve to engine speed
• …
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14-06-13
150
135
120
105
90
75
60
45
30
15
0
More preparation / car
Power (KW)
Principle
Rpm (1/mn)
0
1000 2000 3000 4000 5000
• Gear points calculation
based on balance betw.
power required and
power available by
engine in each gear
• Datas search (power
curve for specific car,
transmission ratios,…)
• Maximum possible gear
must be used
 Room for errors !
• Gear pts calculation
Slide 10
Outline
TÜV SÜD Auto Service GmbH
14-06-13
1
History
2
Process
3
Comparison WLTP / NEDC
4
Conclusion
Slide 11
Comparison WLTP / NEDC
Process comparison
120
100
140
Speed [km/h]
140
WLTP
120
100
80
80
60
60
40
40
20
20
Speed [km/h]
NEDC
0
0
0
200
400 time (s) 600
800
1000
1200
0
200
400
600
time [s]
800
1000
1200
1400
1600
1800
• Only one cycle version for all vehicles
• 3 Classes + Subclass + downscaling possible
• 20 min non dynamic cycle (constant speed)
• 30 min dynamic cycle based on real driving data
• Fixed gear shift points for all cars
• Car technical specifications not required
• Same gas and FC formulas
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• Gear points is different for each car
• Many technical spec. required for Gear pts
• Same gas and FC formulas
• New Test Mass definition (for bench inertia simul.)
14-06-13
Slide 12
Comparison WLTP / NEDC
Fuel consumption comparison (average from 3 tests)
Diesel Manual 6 Gears
10.00
9.23 9.32
NEDC
Fuel consumption [l/100km]
9.00
WLTP
8.00
7.19
6.99
7.00
6.02
6.00
6.72
5.99
6.21
5.00
4.00
3.00
2.00
1.00
0.00
Phase 1
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Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 13
Comparison WLTP / NEDC
Exhaust emission comparison (average from 3 tests)
Diesel Manual 6 Gears - NOx
1200.0
NEDC
1000.0
Bag results [mg/km]
WLTP
968.7
800.0
619.7
600.0
461.1
454.8
400.0
357.3
209.8
200.0
179.6
162.2
0.0
Phase 1
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Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 14
Comparison WLTP / NEDC
Exhaust emission comparison (average from 3 tests)
Gasoline Manual 5 Gears - HC
180
168
NEDC
Bag results [mg/km]
160
WLTP
140
120
102
100
80
60
40
40
26
20
4
3
9
2
0
Phase 1
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Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 15
Comparison WLTP / NEDC
Fuel consumption comparison – Modal analysis
Diesel Manual 6 Gears - Total fuel consumption
20.000
200.000
WLTP FC (l/100km)
NEDC FC (l/100km)
WLTP speed (km/h)
16.000
NEDC Speed (km/h)
180.000
160.000
14.000
140.000
12.000
120.000
10.000
100.000
8.000
80.000
7,18
6.000
6,78
60.000
4.000
40.000
2.000
20.000
0.000
0
TÜV SÜD Auto Service GmbH
200
400
600
14-06-13
800
Time (s)
1000
1200
1400
1600
0.000
1800
Slide 16
Spped [km/h]
Fuel consumption [l/100km]
18.000
Outline
TÜV SÜD Auto Service GmbH
14-06-13
1
History
2
Process
3
Comparison WLTP / NEDC
4
Conclusion
Slide 17
Conclusion
Summary
Benefits for all
OEM challenges
Testing challenges
150
135
120
105
90
75
60
45
30
15
0
Power (KW)
Closer to reality
Rpm (1/mn)
0
• WLTC created from
real driving data
• From city to
highway simulation
• Optimal gear pts for
each car
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• Better implemention
of FC and emission
reduction
• One procedure for
future type approval
• Unified engine
design worldwide
14-06-13
1000 2000 3000 4000 5000
• 5 gears vehicles are
disadvantaged
• Much more
preparation per car
• More NOx emissions
 major challenge
(however should be
ok with SCR)
• Many technical data
needed for gear
points calculation
• Errors in gear points
calculation possible
Slide 18
Comparison WLTP / NEDC
Conclusions
Tendency:
• FC:
 5 gears: Better FC for NEDC (because phase 4 WLTC FC is high)
 6 gears: Better FC for WLTC (because total FC is brought down by phase 2,3,4)
• HC:
 Much less HC for WLTC (because more distance with warm CAT driven  low HC phase 2,3,4)
• CO:
 Mixed results, tendency to lower WLTP results
• NOx:
 Significant y worst for WLTC  problem for OEM’s in future for type approval with WLTC without SCR
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14-06-13
Slide 19
Backup
TÜV SÜD Auto Service GmbH
14-06-13
Slide 20
Comparison WLTP / NEDC
Statistical comparison
WLTC - Class 3
Phase
Duration [s]
Stop duration [s]
stops [%]
Distance [km]
Max. speed [km/h]
Ø speed w/o stops [km/h]
Ø speed with stops [km/h]
Max. acceleration [m/s2]
Ø acceleration [m/s2]
•
•
•
•
•
NEDC
1
2
3
4
Total
1
2
Total
589
433
455
323
1800
780
400
1180
156
48
31
7
242
240
38
278
26,5
11,1
6,8
2,2
13,4
30,77
9,55
23,6
3,095
4,756
7,158
8,254
23,262
3,976
6,955
10,93
56,5
76,6
97,4
131,3
131,3
50,0
120,0
120,0
25,7
44,5
60,8
94,0
53,8
25,93
69,36
43,1
18,9
39,5
56,6
92,0
46,5
18,35
62,59
33,35
1,5
1,6
1,6
1,0
1,6
1,042
0,833
1,042
0,48
0,44
0,37
0,30
0,41
0,64
0,35
0,528
WLTP phase 1 similar to NEDC phase 1
WLTP max acceleration is 53,6% higher than NEDC
WLTP average speed with stops is 39,4% higher than NEDC
WLTP max speed is 9,4% higher than NEDC
WLTP has 1,76 times less stops than NEDC
TÜV SÜD Auto Service GmbH
14-06-13
Slide 21
Comparison WLTP / NEDC
Fuel consumption comparison
Gasoline Manual 5 Gears - Calculated Gear pts
9.00
8.25 8.30
NEDC
Fuel consumption [l/100km]
8.00
WLTP
6.76
7.00
6.49 6.42
6.01
6.00
5.45
5.48
5.00
4.00
3.00
2.00
1.00
0.00
Phase 1
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Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 22
Comparison WLTP / NEDC
Exhaust emission comparison
Gasoline Manual 5 Gears - CO
1400
NEDC
1201
1200
WLTP
Bag results [mg/km]
1086
1000
800
736
628
600
400
335
175
200
101
74
0
Phase 1
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Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 23
Comparison WLTP / NEDC
Exhaust emission comparison
Gasoline Manual 5 Gears - NOx
35
NEDC
30
WLTP
Bag results [mg/km]
30
25
20
18
15
12
11
10
5
5
2
2
2
0
Phase 1
TÜV SÜD Auto Service GmbH
Phase 2
14-06-13
Phase 3
Phase 4
Total
Slide 24