Or: why we should get over our obsession with the tailpipe. The common perception is that the tailpipe is main source of pollutant emissions from vehicles, while the occupant of the vehicle can be safely sealed away from them. In reality, cabin air is affected by emissions from multiple sources, at the same time as the tailpipe has become much cleaner. To assess the latest state of evidence, this presentation will cover: • How low are tailpipe emissions now in real-world conditions? • What are the other sources of emissions? • Is filtration of exhaust gas more effective than cabin air? • In what circumstances is it more polluted inside a car than outside? • If we regulate ambient air quality, why should we not regular in-cabin air quality?

1. Is vehicle cabin air now dirtier than what comes
out of the tailpipe?
Nick Molden
12 October 2021

2. CONFIDENTIAL © Emissions Analytics 2020
When it comes to the pursuit for improved air quality, we believe in the power of
clarity, transparency and integrity. With real-world data we can meet emissions
challenges – instilling trust and confidence in our industry partners and public.
It’s with our commitment and independence we are able to make a significant
contribution toward positive change and to achieve enduring results.
Our Belief
65

3. CONFIDENTIAL © Emissions Analytics 2021
• Founded in 2011
• Headquartered in the UK
• Operations in Germany, USA and South Korea
• Independent testing house specialising in real-world emissions testing
• Over 2,500 vehicles/machines PEMS tested across passenger, commercial and off-road
• Largest commercially available database of real-world emissions data
• We work with regulators, OEMs, Tier 1/2 suppliers, fuel and chemical companies, fleets,
consumer media
• Leads standardisation of new methods through CEN
Introduction
66

4. Test methodologies

5. CONFIDENTIAL © Emissions Analytics 2021
• Core: CO2, CO, NO, NO2, NOx, exhaust temperature
• Using regulatory-grade PEMS from Sensors, Inc
• Measurements at 1Hz
• Weather station: temperature, humidity, pressure
• OBD: typically speed, rpm, coolant temperature, engine load,
throttle position, manifold pressure
• PN, particularly for EU gasoline and hybrids
• Custom integrated NH3 sensor
Measurements – PEMS
68

6. CONFIDENTIAL © Emissions Analytics 2021
Measurements – volatile organic compounds
69
• Two-dimensional gas chromatography with mass
spectrometry
• INSIGHT flow modulator from SepSolve Analytical
for separation
• BENCH-TOF time-of flight mass spectrometer
• Thermal desorption tube sampling from Markes
International

7. CONFIDENTIAL © Emissions Analytics 2021
Portable in-cabin measurement system
70
• Particle number (down to 15nm), CO2, CO, NO2

8. Tailpipe emissions

9. CONFIDENTIAL © Emissions Analytics 2021
• Diesel NOx under control
since RDE around 2018
• Both diesel and gasoline
NOx tending to very low
levels
• PN emissions in decline and
always well under 6x1011
#/km limit
• What about unregulated
pollutants?
How low are tailpipe emissions now?
72

10. CONFIDENTIAL © Emissions Analytics 2021
• 8 gasoline vehicles
• Mix of hybridisation levels
• PHEV in engine mode
• 2020 or 2021 model year
• EQUA test cycle
• Tested May-July 2021
 Three-way catalysts can produce N2O, CH2O
 VOCs including aldehydes, ketones, alcohols and PAHs may also be generated
 What else should Euro 7 consider?
Test programme
73

11. CONFIDENTIAL © Emissions Analytics 2021
• xx
Regulated pollutant test results
74
Model Year Make Model Fuel/powertrain CO2 (g/km) CO
(mg/km)
NOx
(mg/km)
PN
(x10^11)
2021 Renault Clio Gasoline 124.6 61 6 0.015
2021 Volkswagen Polo Gasoline 130.2 14 6 0.083
2021 Kia Rio Gasoline MHEV 139.9 39 7 0.575
2021 Ford Focus Gasoline MHEV 126.5 194 3 0.620
2021 Skoda Octavia Gasoline 116.6 11 14 0.003
2020 Mini Countryman Gasoline PHEV 176.9 113 1 0.122
2021 Subaru Forester Gasoline FHEV 184.3 143 6 2.198
2021 Peugeot 208 Gasoline 134.1 251 8 0.685
Average 141.6 103 6 0.538
Average exceedance factor 1.5 0.1 0.1 0.1

12. CONFIDENTIAL © Emissions Analytics 2021
• Powerful greenhouse gas
• Quantified using N2O standard
Nitrous oxide results
75
Model Year Make Model Fuel/powertrain N2O (mg/km)
Urban Rural Motorway
2021 Renault Clio Gasoline 0.256 4.794 3.177
2021 Volkswagen Polo Gasoline 0.927 3.933 0.389
2021 Kia Rio Gasoline MHEV 0.678 2.335 1.742
2021 Ford Focus Gasoline MHEV 0.727 3.199 3.504
2021 Skoda Octavia Gasoline 1.085 4.588 3.978
2020 Mini Countryman Gasoline PHEV 0.718 2.778 1.753
2021 Subaru Forester Gasoline FHEV 0.141 2.194 1.624
2021 Peugeot 208 Gasoline 0.781 2.077 1.898
Average 0.664 3.237 2.258

13. CONFIDENTIAL © Emissions Analytics 2021
• Carcinogen, serious irritant
• Quantified using CH2O standard
Formaldehyde results
76
Model Year Make Model Fuel/powertrain CH2O (mg/km)
Urban Rural Motorway
2021 Renault Clio Gasoline 0.380 0.400 0.340
2021 Volkswagen Polo Gasoline 0.160 0.250 0.200
2021 Kia Rio Gasoline MHEV 0.130 0.110 0.110
2021 Ford Focus Gasoline MHEV 0.180 0.240 0.150
2021 Skoda Octavia Gasoline 0.170 0.330 0.260
2020 Mini Countryman Gasoline PHEV 0.110 0.210 0.110
2021 Subaru Forester Gasoline FHEV 0.190 0.430 0.170
2021 Peugeot 208 Gasoline 0.160 0.250 0.140
Average 0.185 0.278 0.185

14. CONFIDENTIAL © Emissions Analytics 2021
• Affect lungs, liver, kidney, brain +
headaches, dizziness
• Quantified using toluene equivalence
Alkanes, alkenes‚ alkynes and
cyclo- results
77
Model Year Make Model Fuel/powertrain Alkanes etc (ng/km)
Urban Rural Motorway
2021 Renault Clio Gasoline 1627.2 5817.1 3333.7
2021 Volkswagen Polo Gasoline 2872.2 6309.3 4564.0
2021 Kia Rio Gasoline MHEV 3250.6 3877.2 3448.7
2021 Ford Focus Gasoline MHEV 4873.7 5515.1 3232.6
2021 Skoda Octavia Gasoline 2890.9 2891.6 1775.5
2020 Mini Countryman Gasoline PHEV 972.4 2774.5 1193.8
2021 Subaru Forester Gasoline FHEV 4089.4 14287.7 8111.6
2021 Peugeot 208 Gasoline 6142.8 6834.5 5997.0
Average 3339.9 6038.4 3957.1

15. CONFIDENTIAL © Emissions Analytics 2021
• Often carcinogenic
• Quantified using toluene equivalence
PAH and N-compounds
78
Model Year Make Model Fuel/powertrain PAH and N-compounds (ng/km)
Urban Rural Motorway
2021 Renault Clio Gasoline 15.8 71.6 31.5
2021 Volkswagen Polo Gasoline 266.0 292.1 210.5
2021 Kia Rio Gasoline MHEV 294.0 227.2 205.0
2021 Ford Focus Gasoline MHEV 281.1 333.5 121.1
2021 Skoda Octavia Gasoline 428.1 322.4 205.0
2020 Mini Countryman Gasoline PHEV 214.3 285.0 126.3
2021 Subaru Forester Gasoline FHEV 287.8 259.0 182.4
2021 Peugeot 208 Gasoline 211.6 469.6 206.6
Average 249.9 282.6 161.0

16. Other sources of emissions

17. CONFIDENTIAL © Emissions Analytics 2020
Tyre wear testing
80

18. CONFIDENTIAL © Emissions Analytics 2021
• Most mass is shed at 10μm end of distribution
• Large number of ultrafine particles down to 10nm
• Concentration >400,000 #/cm3 at the low size end
• Ultrafine peaks when tyre surface hotter
• Contribute to both air and marine pollution
• 64 mg/km for new tyres, averaging 32 mg/km
• <1 mg/km tailpipe for new vehicles
Tyre wear emissions
81

19. Filtration effectiveness

20. CONFIDENTIAL © Emissions Analytics 2021
• Euro 6 diesel, with DPF
• Matching CPCs in front of and
behind vehicle
• Canisters deployed in front of
air intake
• Neutralised by engine and
DPF
• Underlying effect of cleaning
air
• Can be offset during high load
and filter regeneration
Measuring tailpipe filtration
83
1
10
100
1000
10000
100000
1000000
10000000
1
47
93
139
185
231
277
323
369
415
461
507
553
599
645
691
737
783
829
875
921
967
1013
1059
1105
1151
1197
1243
1289
1335
1381
1427
1473
1519
1565
1611
1657
1703
1749
1795
1841
1887
1933
1979
2025
2071
2117
2163
2209
2255
2301
Particle
number
concentration,
#/cm3
Time, seconds
Front of vehicle Rear of vehicle
Canister2
Canister1
Vehicle on

21. CONFIDENTIAL © Emissions Analytics 2021
• Real-world methodology
• Being standardised with CEN Workshop 103
Measuring in-cabin pollution
84
0
50000
100000
150000
200000
250000
1
71
141
211
281
351
421
491
561
631
701
771
841
911
981
1051
1121
1191
1261
1331
1401
1471
1541
1611
1681
1751
1821
1891
1961
2031
2101
2171
2241
2311
2381
2451
2521
2591
2661
2731
2801
2871
2941
3011
3081
3151
3221
3291
3361
3431
3501
3571
3641
3711
3781
3851
3921
3991
4061
Particle
number
concentration,
#/cm
3
Time, seconds
Inside vehicle Outside vehicle
Recirculationon Recirculationoff

22. CONFIDENTIAL © Emissions Analytics 2021
• xx
Tyre wear emissions
85
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
500000
1
94
187
280
373
466
559
652
745
838
931
1024
1117
1210
1303
1396
1489
1582
1675
1768
1861
1954
2047
2140
2233
2326
2419
2512
2605
2698
2791
2884
2977
3070
3163
3256
3349
3442
3535
3628
3721
3814
3907
4000
4093
4186
4279
4372
4465
4558
4651
4744
4837
4930
Particle
number
concentration
(#/cm3)
Time(seconds)
Inside
Outside
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1
96
191
286
381
476
571
666
761
856
951
1046
1141
1236
1331
1426
1521
1616
1711
1806
1901
1996
2091
2186
2281
2376
2471
2566
2661
2756
2851
2946
3041
3136
3231
3326
3421
3516
3611
3706
3801
3896
3991
4086
4181
4276
4371
4466
4561
4656
4751
4846
4941
Particle
number
concentration
(#/cm3)
Time(seconds)
Inside
Outside
Good filtration:
Hyundai Kona
CAQI = 0.36
Poor filtration:
Lexus ES
CAQI = 4.32
Recirculation on Recirculation off Recirculation on Recirculation off

23. CONFIDENTIAL © Emissions Analytics 2021
• 97 vehicles
• Recent US models
• Tested in California
• CAQI results averaged by
manufacturer
• Fresh air vs recirculation
mode
• Moderate correlation
suggests importance of
filtration strategy
Comparative test programme
86
Acura
BMW
Chevrolet
Chrysler
Dodge
Ford
GMC
Honda
Hyundai
Infiniti
Jaguar
Jeep
Kia
Lexus
Lincoln
Mazda
Mercedes-Benz
Mitsubishi
Nissan
Ram
Subaru
Tesla
Toyota
Volkswagen
Volvo
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.00 0.50 1.00 1.50 2.00 2.50
PN
filtration
rate
-
recirculation
on
PN filtration rate - recirculation off

24. CONFIDENTIAL © Emissions Analytics 2021
Putting tailpipe and cabin together…
87

25. CONFIDENTIAL © Emissions Analytics 2021
• Average CAQI is 1.2
• Cabin slightly more polluted than outside on average
• Ambient sees big particulate spikes, which can persist when inside
• Before regulation, measurement and rating necessary
• Potential for a quick win, as better filtration is relatively inexpensive
• Better than Euro 7, which may just regulate existing low emissions even further?
• Let’s stand back and consider the holistic environmental and health impacts of vehicles to
prioritise action
Should we regulate in-cabin air?
88

26. Thank you.
Nick Molden
Chief Executive Officer
nick@emissionsanalytics.com
+44 (0)20 7193 0489