REPORT FROM THE COMMISSION Commission report under Article 12(3) of Regulation (EU) 2019/631 on the evolution of the real-world CO2 emissions gap for passenger cars and light commercial vehicles and containing the anonymised and aggregated real-world datasets referred to in Article 12 of Commission Implementing Regulation (EU) 2021/392
Date: 2024-03-18
Institutions: Directorate-General for Climate Action, European Commission
Subjects: data collection, energy consumption, environmental monitoring, greenhouse gas, light-duty vehicle, motor car, motor fuel, motor vehicle pollution, pollution control measures, reduction of gas emissions

EN 

  EN 

   EUROPEAN COMMISSION  Brussels, 18.3.2024  COM(2024) 122 final  REPORT FROM THE COMMISSION Commission report under Article 12(3) of Regulation (EU) 2019/631 on the evolution of the real-world CO2 emissions gap for passenger cars and light commercial vehicles and containing the anonymised and aggregated real-world datasets referred to in Article 12 of Commission Implementing Regulation (EU) 2021/392    {SWD(2024) 59 final}  
 
 
1. 

INTRODUCTION 

Road transport is responsible for about one fifth of the European Union’s (EU) greenhouse 
gas emissions. Within  road transport  emissions,  light-duty  vehicles (passenger cars  and 
light commercial vehicles) are responsible for around 70% of the total (1).  

To reach climate neutrality in the EU by 2050, the European Green Deal (2) calls for a 90% 
reduction in greenhouse gas emissions from transport compared to 1990 levels. Regulation 
(EU) 2019/631 (3), which sets out the CO2 emission performance standards for new light-
duty vehicles, is one of the key policy instruments put in place to achieve this goal. 

The official CO2 emission values of vehicles, as determined during type-approval, are used 
to  determine  whether  manufacturers  comply  with  the  targets  under  the  Regulation.  As 
such, the effectiveness of these targets in reducing CO2 emissions, as well as the robustness 
of  the  CO2  emission  monitoring  system,  depend  on  how  well  those  official  test  values 
represent the ‘real-world’ emissions of vehicles out on the road. This representativeness is 
important for the environmental integrity, transparency, and reliability of the monitoring 
system, and therefore also for consumers’ trust. 

Several measures have been put in place over recent years to make sure test values come 
as  close  to  reality  as  possible.  In  2017,  the  Worldwide  harmonised  Light  vehicle  Test 
Procedure (WLTP) (4) was introduced, which was designed to better represent real-world 
driving conditions. As part of the new procedures, new vehicles have to be equipped with 
on-board  fuel  consumption  monitoring  devices  (‘OBFCM  devices’).  This  requirement 
applies  for  new  M1  vehicles  (cars)  registered  since  2021  and  new  N1  vehicles  (vans) 
registered since 2022. In addition, Regulation (EU) 2019/631 introduced a requirement for 
national  authorities  to  verify  the  correctness  of  the  official  WLTP  CO2  values  through 
testing vehicles already in-service, i.e. used on the roads. 

Regulation (EU) 2019/631 also tasked the Commission with monitoring the ‘real-world’ 
CO2 emissions of vehicles on the road, using the data read out from the OBFCM devices, 
and comparing it with the corresponding official WLTP data (5). 

(1)   https://www.eea.europa.eu/data-and-maps/data/data-viewers/greenhouse-gases-viewer  

(2)  COM/2019/640 final, 11.12.2019 

(3)  Regulation (EU) 2019/631 of the European Parliament and of the Council of 17 April 2019 setting CO2 
emission  performance  standards  for  new  passenger  cars  and  for  new  light  commercial  vehicles  and 
repealing Regulation (EC) No 443/2009 and (EU) No 510/2011 (OJ L 111, 25.4.2019, p. 13) 

(4)   Commission Regulation (EU) 2017/1151 of 1 June 2017 supplementing Regulation (EC) No 715/2007 
of  the  European  Parliament  and  of  the  Council  on  type-approval  of  motor  vehicles  with  respect  to 
emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle 
repair and maintenance information, amending Directive 2007/46/EC of the European Parliament and 
of  the  Council,  Commission  Regulation  (EC)  No  692/2008  and  Commission  Regulation  (EU)  No 
1230/2012 and repealing Commission Regulation (EC) No 692/2008 (OJ L 175, 7.7.2017, p. 1) 

(5)   The  procedures  for  collecting  and  reporting  this  ‘real-world’  data  and  for  comparing  it  with  the 
corresponding WLTP data are set out in Commission Implementing Regulation (EU) 2021/392  (OJ L 
77, 5.3.2021, p. 8) 

 
      
  
 
This report is the first on the implementation of that ‘real-world’ CO2 emission monitoring, 
focusing on data reported in 2022, for vehicles first registered in 2021. The official WLTP 
data used for the comparison was finalised and adopted in August 2023 (6).  

This report includes an overview of the data received and processed by the Commission 
(Section 2), the main results of the analysis (Section 3), an assessment of how the real-
world data may be used in the future (Section 4), and the conclusions that can be drawn at 
this stage (Section 5). 

The Staff Working Document (7) accompanying this report sets out the methodology used 
for processing and analysing the real-world data and contains more detailed results. It also 
contains the first of the anonymised and aggregated annual datasets per manufacturer that 
form the basis for the Commission to monitor the gap between the WLTP and real-world 
values (8). 

2.  DATASET  

2.1.  Data sources and data processing 

According to Implementing Regulation (EU) 2021/392, real-world data must be collected 
by  both  vehicle  manufacturers  and  Member  States  and  reported  to  the  European 
Environment Agency (EEA). Manufacturers may rely on data transfer over-the-air directly 
from  the  vehicle  or  collect  this  data  through  their  authorised  dealers  or  repairers  when 
vehicles are brought in for service or repairs. Member States have been required to collect 
the real-world data during roadworthiness tests since 20 May 2023. 

This first report is based on the real-world data collected by vehicle manufacturers 
throughout 2021 on their cars and vans equipped with OBFCM devices. Real-world 
data was received for 988 231 vehicles out of a total of 9 821 479 vehicles first registered 
in 2021 in the EU, Iceland or Norway (9). This included 916 216 cars and 12 301 vans (10), 
which corresponds to 10.6% and 1.0%, respectively, of those vehicles first registered in 
2021 (11). 

Before  being  analysed,  the  data  was  processed  and  aggregated  in  several  steps. 
Unrepresentative data, inconsistent data, outliers, and vehicles out-of-scope were removed. 

(6)  Commission Implementing Decision (EU) 2023/1623 of 3 August 2023 specifying the values relating 
to the performance of manufacturers and pools of manufacturers of new passenger cars and new light 
commercial  vehicles  for  the  calendar  year  2021  and  the  values  to  be  used  for  the  calculation  of  the 
specific emission targets from 2025 onwards, pursuant to Regulation (EU) 2019/631 of the European 
Parliament  and  of  the  Council  and  correcting  Implementing  Decision  (EU)  2022/2087  (OJ  L  111, 
25.4.2019, p. 13.) 

(7)  SWD(2024) 59 

(8)  In accordance with Article 12 of Implementing Regulation (EU) 2021/392. 

(9)  The total number of new cars and vans referred to do not include vehicles not in-scope for OBFCM 

(pure electric vehicles, fuel cell electric vehicles, natural gas vehicles), and E85 vehicles. 

(10)  59 714 vehicles could not be matched with the 2021 WLTP data. 

(11)  Data shall be collected by manufacturers either over-the-air via direct data transfer from the vehicle, or, 
where data is not collected this way, data shall be collected each time the vehicle is brought in for service 
or repairs, unless the vehicle owner expressly refuses to make that data available. See also Section 3.2.1.  

2 

 
 
 
In particular, vehicles with a mileage below 500 km were filtered out, which removed 27% 
of  cars  in  the  dataset.  Overall,  63%  of  the  reported  vehicles  were  retained  in  the  final 
dataset. Further details on the process can be found in the accompanying Staff Working 
Document.  

2.2. 

Final 2021 real-world dataset 

The  final  dataset,  which  was  used  for  the  further  calculations,  is  presented  in  Table  1 
below. It includes 617 194 cars (7.2% of cars first registered in 2021) and 6 667 vans (0.6% 
of vans first registered in 2021).  

Overall, only a small number of manufacturers reported data from a significant share 
of their vehicles registered in 2021. Further efforts by manufacturers will be required 
to  significantly  improve  the  fleet  coverage  in  the  coming  years.  While  for  cars  this 
dataset  is  sufficient  to  draw  preliminary  conclusions,  there  was  an  uneven  distribution 
between data presented by manufacturers (see Section 3.2.1). For vans, the fleet coverage 
is very limited, which is explained by the fact that Class II and III vans (i.e. those weighing 
over 1 305 kg), which represent the vast majority of the fleet, are only required to have 
OBFCM devices as of 2022. As such, the real-world dataset for vans cannot be considered 
representative of the 2021 registrations, and this report’s analysis focuses solely on cars. 

Among cars, diesel and plug-in hybrid electric vehicles represent a higher share of the real-
world dataset than of the overall 2021 registrations. Further calculations and gap analyses 
are therefore undertaken for each powertrain/fuel type.  

Table 1: Final real-world dataset 

Powertrain/fuel 
type 

Number 
of 
vehicles 
reported 

Petrol 

391 329 

Diesel 

301 995 

E85 

Other fuels 

Plug-in hybrid 
(petrol) 

Plug-in hybrid 
(diesel) 

TOTAL  
cars 

2 084 

697 

191 197 

28 914 

916 216 

Number of 
vehicles 
after 
processing 
(% 
retained) 

Cars 

274 451 
(70.1%) 

219 003 
(72.5%) 

0 

0 

98 847 
(51.7%) 

24 893 
(86.1%) 

617 194 
(67.4%)  

Vans 

3 

Total 2021 
registrations by 
powertrain/fuel 
type 

Share of 2021 
registrations 
retained per 
powertrain/fuel 
type 

5 495 708 

2 229 388 

6 026 

215 798 

848 251 

55 805 

5.0% 

9.8% 

0% 

0% 

11.7% 

44.6% 

8 629 152 

7.2% 

 
Petrol 

1 891 

Diesel 

10 053 

Other fuels 

Plug-in hybrid 
(petrol) 

Plug-in hybrid 
(diesel) 

30 

326 

1 

TOTAL 
vans 

12 301 

988 
(52.3%) 

5 593 
(55.6%) 

0 

86  
(25.8%) 

0 

6 667  
(54.2%) 

44 475 

1 139 405 

58 488 

1 501 

4 

2.2% 

0.5% 

0% 

5.7% 

0% 

1 185 385 

0.6 % 

2.3.  Representativeness of the final 2021 real-world dataset  

To assess whether the cars covered by the final 2021 real-world dataset are representative 
of the vehicles first registered in 2021 (per powertrain/fuel type), their average WLTP CO2 
emissions and mass are compared, as shown in Table 2.  

This  indicates  that,  on  average,  the  petrol  and  diesel  cars  in  the  real-world  dataset  are 
around  7%  heavier  than  the  average  new  car  registered  in  2021,  and  their  WLTP  CO2 
emissions are around 6-8% higher. A similar trend is observed for petrol plug-in hybrid 
electric cars. This may bias results. 

This is related to the fact that the 2021 real-world dataset is dominated by vehicles from a 
small  number  of  manufacturers  (see  Section  3.2.1),  many  of  which  having  over-the-air 
capabilities  allowing  data  transmission  directly  to  the  manufacturers.  In  2021,  such 
vehicles were more prominently present in the heavier fleet segments. 

Table  2:  Representativeness  of  the  real-world  dataset  compared  to  the  vehicles  first 
registered in 2021 (cars) (12) 

Powertrain/fuel type 

Average WLTP CO2 
emissions (g CO2/km) 

Average mass in running 
order (kg) 

real-world 
dataset 

2021 first 
registrations 

real-world 
dataset 

2021 first 
registrations 

Petrol 

Diesel 

Petrol + Diesel 

Plug-in hybrid (petrol) 

Plug-in hybrid (diesel) 

Plug-in hybrid (all) 

145.0 

153.0 

148.5 

40.3 

37.2 

39.6 

134.8 

144.7 

137.7 

37.7 

37.2 

37.7 

1 404 

1 747 

1 554 

1 955 

2 281 

2 021 

1 317 

1 627 

1 407 

1 899 

2 291 

1 923 

(12)  See note 9, page 2. 

4 

 
 
 
3.  RESULTS 

The average real-world and WLTP CO2 emissions and fuel consumption, as well as the 
gap between those real-world and WLTP values are calculated at fleet level and for each 
manufacturer separately.  

The calculation methodology and results are presented in more detail in the Staff Working 
Document, which also contains the data at country-level, and information regarding the 
electric energy consumption of the plug-in hybrid electric vehicles. 

3.1. 

Fleet-wide  assessment  of  the  average  CO2  emissions,  fuel  consumption 
and real-world gap 

Table 3 summarises the main findings for cars. It shows, for each of the powertrain/fuel 
type groups, the average real-world fuel consumption and CO2 emissions, as well as the 
corresponding WLTP values, and the relative gap between those average real-world and 
WLTP values. For the gap, both the arithmetic average and the km-weighted average are 
presented,  as  the  latter  should  provide  a  better  indication  of  the  total  additional  fuel 
consumption and CO2 emissions due to the real-world gap. 

Table  3:  Average  real-world  and  WLTP  fuel  consumption,  CO2  emissions,  and  gap 
between real-world and WLTP values (cars) 

Average fuel 
consumption  
(l/100 km) 

Average CO2 
emissions 
(g/km) 

Gap (%) (13) 

Powertrain/fuel type 

real-
world 

WLTP 

real-
world 

WLTP  average  km-weighted 

average 

Petrol 

Diesel 

Petrol + Diesel 

Plug-in hybrid (petrol) 

Plug-in hybrid (diesel) 

Plug-in hybrid (all) 

7.89 

6.88 

7.44 

5.97 

5.83 

5.94 

6.38 

179.8  145.3 

5.82 

181.0  153.2 

6.13 

180.3  148.8 

1.76 

135.9 

40.2 

1.41 

153.3 

37.2 

1.69 

139.4 

39.6 

23.7 

18.1 

21.2 

238 

312 

252 

20.4 

16.7 

18.1 

251 

318 

267 

In their first year of use, the average real-world gap for new vehicles registered in 
2021 was 23.7% (34.6 g CO2/km) for petrol cars and 18.1% (27.8 g CO2/km) for diesel 
cars, giving a combined average gap of 21.2% (31.6 g CO2/km). The km-weighted average 
gaps  are  somewhat  lower:  20.4%  (30.4  g  CO2/km)  for  petrol  cars  and  16.7%  (25.3  g 
CO2/km) for diesel cars.  

This observed gap for 2021 registrations indicates that the switch from the old NEDC (New 
European Driving Cycle) to the new WLTP testing procedure has about  halved the gap 
between the real-world emissions and those measured through laboratory testing. By 2017, 

(13)  The gap is expressed here as a % deviation of real-world CO2 emissions from the WLTP CO2 value, 
where a positive deviation indicates that the former are larger. It is the same for both CO2 emissions and 
fuel consumption, except for the cases combining petrol and diesel values, where the CO2 gap is shown. 

5 

 
 
 
 
the gap between real-world CO2 emissions and CO2 emissions measured under the NEDC 
procedure had grown to around 40% (14). This rising gap motivated the switch from NEDC 
to WLTP, and the requirement to fit vehicles with OBFCM devices.  

For  the  Impact  Assessments (15) underpinning  the  revision  of  the  CO2  emission 
performance standards for cars and vans, the Commission assumed that the WLTP CO2 
emissions of combustion engine cars were on average 21% higher than those calculated 
with  the  NEDC,  which  was  later  confirmed  by  a  JRC  study (16).  This  ratio  implies  an 
emissions gap of about 16% between the real-world emissions and the WLTP ones. For 
the year 2021, the gap observed is compatible with the 2021 gap assumed for the Impact 
Assessments. Such a gap was anticipated, as there are different factors affecting real-world 
emissions which cannot all be fully replicated in a laboratory test.  

The observed gap also means that the real-world fuel consumption experienced by drivers 
remains on average 1-1.5 l/100km higher than what is indicated on the official documents.  

An analysis by mass showed that while lighter petrol and diesel vehicles have a real-world 
gap between 20-40 g CO2/km, for heavy vehicles, such as SUVs and luxury vehicles, the 
gap is 1.5-2.5 times greater, which adds to their already higher WLTP CO2 emissions. 

For the new plug-in hybrid electric cars registered in 2021, the average real-world CO2 
emissions  (139.5  g  CO2/km)  were  only  23%  lower  than  for  conventional  cars  (180.3  g 
CO2/km), and 3.5 times (100 g CO2/km) higher than what the WLTP test indicated (39.5 
g  CO2/km)  –  see  Figure  1.  For  those  vehicles,  the  calculation  of  their  WLTP  fuel 
consumption and CO2 emissions takes into account a utility factor, which is the expected 
share of distance driven in electric mode. On the road, the CO2 emissions of those vehicles 
will depend to a great extent on the real share of distance driven fully electrically, which 
in  turn  depends  on  the  actual  recharging  and  use  patterns,  and  specific  vehicle 
technologies. The large discrepancy found for these vehicles between the real-world and 
the WLTP values shows that they are charged and driven in electric mode much less than 
how they were expected to be used and that assumptions used for calculating the WLTP 
test result do not hold in real-world conditions.  

(14)  Pavlovic,  J.,  Clairotte,  M.,  Anagnostopoulos,  K.,  Arcidiacono,  V.,  Fontaras,  G.  and  Ciuffo,  B., 
Characterisation  of  real-world  CO2  variability  and  implications  for  future  policy  instruments,  EUR 
28734 EN, Publications Office of the European Union, Luxembourg, 2017, ISBN 978-92-79-72096-3, 
doi:10.2760/839690, JRC107796. 

(15)  SWD(2017)650 final and SWD(2021)613 final. 

(16) Chatzipanagi, A., Pavlovic, J., Ktistakis, M., Komnos, D. and Fontaras, G., Evolution of European light-
duty  vehicle  CO2  emissions  based  on  recent  certification  datasets,  Transportation  Research  Part  D-
Transport and Environment, ISSN 1361-9209, 107, 2022, p. 103287, JRC127295. 

6 

 
 
 
Figure 1: Average real-world and WLTP CO2 emissions (cars) 

)

m
k
/
2
O
C
g
(
s
n
o
s
s
m
e
2
O
C

i

i

real-world

WLTP

200

180

160

140

120

100

80

60

40

20

0

Petrol

Diesel

Petrol plug-in hybrid

Diesel plug-in hybrid

3.2.  Manufacturer-level assessment 

3.2.1.  Coverage  

Figure 2 provides an overview of the number of vehicles reported per manufacturer in the 
real-world dataset, both before and after processing, and the extent to which this covers 
their vehicles first registered in 2021.  

This  illustrates  the  very  significant  variability  amongst  manufacturers.  This  can  be 
explained by the different degree to which the available data collection options were used, 
with  only  a  few  manufacturers  making  comprehensive  use  of  over-the-air  data 
transmission. Other manufacturers only collected data from the limited number of vehicles 
that  were  brought  in  for  service  or  repairs  in  the  first  year  after  their  registration.  In 
accordance  with  Regulation  (EU)  2021/392,  manufacturers  will  be  required  to  provide 
reasons for the missing vehicle data as part of their reporting for the following year. 

After data processing, the coverage of the 2021 fleet was rather poor in this first reporting 
year, except for Jaguar Land Rover (43%), Ford Werke GmbH (34%), Mercedes-Benz AG 
(27%), Ford Motor Company (27%) and Volvo (24%). Most of the other manufacturers 
reported  data  for  less  than  5%  of  their  vehicles  first  registered  in  2021.  For  certain 
manufacturers with a high initial coverage before data processing, the low-mileage filter 
reduced a significant number of vehicles. This was the case for Volvo and Jaguar Land 
Rover,  which  had  the  highest  initial  coverage,  but  70%  and  31%  of  their  respective 
reported vehicles had driven less than 500 km. 

The final dataset is dominated by very few manufacturers, in particular Ford Werke GmbH 
(22%)  and  Mercedes-Benz  AG  (21%).  Together  with  Volkswagen  (9%),  Volvo  (8%), 
Renault (7%), and BMW AG (6%), they represent 73% of the final dataset for cars. The 
plug-in hybrid dataset consists primarily of Mercedes-Benz AG (39%), Volvo (19%), and 
Ford Werke GmbH (16%) vehicles.  

7 

 
 
 
 
 
 
Figure  2: Number  of  cars  per  manufacturer,  before  and  after  data  processing:  total 
number  (left)  and  percentage  of  the  manufacturer’s  total  2021  new  registrations 
(right) (17) 

3.2.2.  Average CO2 emissions, fuel consumption and real-world gap  

For  each  manufacturer,  the  average  real-world  fuel  consumption  and  CO2  emissions  as 
well as the gap with the WLTP average values have been calculated. 

In  this  section,  the  results  are  presented  only  for  those  manufacturers  with  over  500 
vehicles reported (for the powertrain/fuel type concerned). The Staff Working Document 
provides additional details.  

The results for different manufacturers may depend on various factors, which will 
require further analysis, also based on subsequent datasets. 

As shown in Figure 3, the average real-world gap for petrol cars differs quite significantly 
across manufacturers, ranging from 10% to 32%, with an average of 23.7%. 

(17)  In  all  Figures  within  Section  3.2,  manufacturers  are  shown  in  decreasing  order  of  their  number  of 

vehicles in the final dataset. 

8 

 
 
 
 
Figure 3: Average real-world CO2 emissions and fuel consumption (left) and gap (right) 
per manufacturer (petrol cars) 

Figure 4 shows that for diesel cars there is less variation across manufacturers in the real-
world gap, which ranges from 15% to 27%, with an average of 18.1%. 

Figure 4: Average real-world CO2 emissions and fuel consumption (left) and gap (right) 
per manufacturer (diesel cars) 

9 

 
 
 
 
 
For petrol plug-in hybrid vehicles, as shown in Figure 5, the average gap per manufacturer 
ranges from 170% to 345%, with an average of 238%. 

Figure 5: Average real-world CO2 emissions and fuel consumption (left) and gap (right) 
per manufacturer (petrol plug-in hybrid electric cars) 

4.  ASSESSING THE FUTURE USE OF THE REAL-WORLD DATA 

This section of the report constitutes the Commission’s assessment under Article 12(3) of 
Regulation  (EU)  2019/631  of  how  the  real-world  data  may  be  used  to  ensure  that  the 
WLTP CO2 emissions and fuel or energy consumption values remain representative of the 
real-world performance over time for each manufacturer. 

At this stage, the following further uses of the real-world data should be considered. 

4.1.  Ensuring that the WLTP values remain representative of the real-world 

emissions 

The main objective of the real-world data monitoring is to track the evolution of the real-
world gap to ensure that the WLTP CO2 emission values remain representative of the real-
world vehicle emissions over time. If the gap does grow over time, this trend should be 
identified as soon  as possible and measures should be  taken  to  ensure that  the growing 
discrepancy is either fixed or adequately accounted for. This could be done, for example, 
through  adjusting  the  WLTP,  correcting  the  WLTP  monitoring  data,  or  setting  targets 
based on real-world emissions. 

At  this  point,  however,  it  is  too  early  to  identify  trends  in  the  gap  size  as  data  is  only 
available for one year. For the following years, it will be necessary to obtain a better and 
more representative coverage of the vehicle fleet to track the real-world data and achieve 
an adequate analysis of this gap over time. 

10 

 
 
4.2.  Revision of the utility factor for plug-in hybrid electric vehicles 

The analysis of the real-world data confirms that the real-world gap for plug-in hybrids is 
significantly higher than for conventional vehicles. A major reason for such a discrepancy 
is the mismatch between the utility factor used during type-approval and the actual vehicle 
charging and driving patterns.  

To tackle this, Commission Regulation (EU) 2023/443 has already introduced changes to 
the calculation of the utility factor to bring it closer to real-world conditions. These changes 
will apply in two consecutive steps, from 2025 and 2027 onwards. Furthermore, by the end 
of 2024 and based on the real-world data collected by then, the Commission will review 
the factor for the second stage.  

4.3.  Using  real-world  data  to  support  the  in-service  verification  of  CO2 

emissions 

As  regards  in-service  verification,  Article  13(2)  of  Regulation  (EU)  2019/631  proposes 
making  use  of  the  data  from  OBFCM  devices.  Delegated  Regulation  (EU)  2023/2867 
setting  out  the  guiding  principles  for  this  in-service  verification  of  CO2  emissions  and 
Implementing  Regulation  (EU)  2023/2866  specifying  the  verification  procedures  have 
recently been adopted. These set out that real-world data can be used as part of the risk 
assessment to support identifying for which vehicle families it makes most sense to verify 
their WLTP CO2 emissions.  

5.  CONCLUSIONS  

The  representativeness  of  the  CO2  emission  values  from  vehicles  is  key  for  the 
environmental  integrity,  transparency,  reliability  of  the  monitoring  system,  and 
therefore also for consumers’ trust. 

This  first  report,  focusing  on  data  for  vehicles  first  registered  in  2021,  initiates  a 
process  of  monitoring  and  reporting  on  the  implementation  of  real-world  CO2 
emissions. In the first year, real-world data was collected from 988 124 vehicles, covering 
10.6% of the cars and 1.0% of the vans first registered in 2021. Following data processing, 
an analysis was performed on a final dataset consisting of 617 194 cars (67% of reported) 
and 6 667 vans (54% of reported).  

The  data  collected  in  this  first  year  presents  a  number  of  limitations  in  terms  of 
coverage,  representativeness  and  quality.  By  definition,  vehicles  reported  in  the  first 
year had been on the road for less than one year. Thereby, except for manufacturers making 
extensive use of over-the-air transmission, data was only collected from the limited number 
of vehicles brought in for service or repairs. For cars, the final dataset covers 7.2% of the 
new cars first registered in the EU in 2021, but mainly consists of vehicles from only four 
manufacturers. It also has a relatively higher share of heavier and diesel vehicles. For vans, 
very limited real-world data was reported in 2021, as the vast majority of them were only 
required to record such data as of 2022. Therefore, no representative analysis for vans was 
possible for this year. 

Overall,  for  most  manufacturers,  the  fleet  coverage  was  below  expectations  and 
further steps should be taken to significantly improve this in the coming years, both 
for cars and vans. In accordance with Regulation (EU) 2021/392, manufacturers will be 

11 

 
required to provide valid reasons for any missing vehicle data as part of their reporting for 
the following years. 

The average gap observed between the real-world and the WLTP CO2 emissions and 
fuel consumption of new cars registered in 2021 was 23.7% (34.6 g CO2/km) for petrol 
cars and 18.1% (27.8 g CO2/km) for diesel cars. This confirms that switching from the 
NEDC  to  the  WLTP  for  determining  the  official  CO2  emission  and  fuel  consumption 
values has roughly halved the real-world gap for conventional vehicles. For the year 2021, 
the gap observed is compatible with the assumptions for the 2021 gap made in the Impact 
Assessments underpinning the revision of the CO2 standards. 

Nevertheless, the real-world fuel consumption experienced by drivers is still around 
one  fifth  higher  than  what  the  official  type-approval  documents  show,  and  it  is 
important that the public is made aware of this. 

This  gap  appears  to  be  particularly  wide  for  heavier  vehicles,  such  as  SUVs  and 
luxury  vehicles,  whose  emissions  are  already  significantly  greater  than  other  cars. 
This larger gap could exacerbate the impacts of wider observed fleet trends, where average 
vehicle  sizes  and  weights  have  been  increasing,  reducing  the  effects  of  fuel  efficiency 
improvements.  The  link  between  the  gap  and  vehicle  mass  will  need  to  be  monitored 
closely in the coming years. 

For  new  plug-in  hybrid  electric  vehicles  registered  in  2021,  the  real-world  CO2 
emissions were  on average  3.5 times (100 g  CO2/km) higher than  the WLTP  ones, 
which confirms that these vehicles are currently not realising their potential, in particular 
as they are not being charged and driven fully electrically as frequently as assumed. To 
better reflect the real-world situation, the Commission has already introduced changes to 
the calculation of the utility factor used for the official test procedure, which will apply as 
of 2025, and may need to be further adjusted based on real-world data. 

While  this  first  data  is  not  yet  broad  or  representative  enough  to  draw  firm 
conclusions, it does provide valuable preliminary insights for car emissions, in how 
the official and real-world CO2 emissions compare across vehicle types and manufacturers.  

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