The document examines the rise of diesel cars in Europe, highlighting the key technological developments and policy changes from the mid-1990s that shaped this trend. It discusses the initial influence of American technology and partnerships between the EU and the European automotive industry that promoted diesel adoption, resulting in significant increases in diesel vehicle registrations in Germany and the UK. The environmental impacts and misconceptions surrounding diesel cars, including emissions trends and the effectiveness of after-treatment technologies, are also evaluated.

1. Europe‘s diesel car boom –
causes & effects
Eckard Helmers e.helmers@umwelt-campus.de
Spinnovation NL
Bristol, October 22, 2015
Eckard Helmers
Environment Campus – University of Applied Sciences Trier, Germany

2. Until the mid 1990s: Europe followed technology leaps initiated in the USA
1960‘s
USA decreased Pb
1970‘s
USA introduced three-wayUSA decreased Pb
content of leaded fuel,
introduced unleaded fuel
USA introduced three-way
catalysts to convert toxic
emissions to N2, CO2
1980‘s
Europe introduced unleaded
fuel and the catalyst
technology for petrol cars;
some 90 % of the cars based
on clean technology in
Germany by year 2000
Europe 1990s‘s,
2000’s:
arrival of the
diesel cars

3. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
Kyoto
protocol
diesel car penetration in world dominating markets.
+ 44 Mio diesel
cars in Europe
1996-2011
Cames & Helmers (2013)
All data are percentages, either annual new car registrations, or annual entire car fleet composition.

4. 40
50
60
%
Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
Diesel car penetration in Germany
+ 7 Mio diesel
cars in Germany
1996-2013
0
10
20
30
40
1990 1995 2000 2005 2010 2015
German fleet
German
registrations
30 % of the
German fleet
Sources: German Federal Motor Transport Authority, ICCT (2014) for UK data

5. 40
50
60
% UK
registrations
Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
34.5 % of the UK fleet
by 2014, up from 7.4 %
in 1994 (UK Dep. for
Transport, 2014)
Diesel car penetration in Germany & the UK
+ 7.9 Mio diesel
cars in UK since 1994
+ 7 Mio diesel
cars in Germany
1996-2013
0
10
20
30
40
1990 1995 2000 2005 2010 2015
German fleet
German
registrations
30 % of the
German fleet
Sources: German Federal Motor Transport Authority, ICCT (2014) for UK data

6. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
principal questions
• who has initiated this techn. change and why?
• how was this techn. change realised/directed?
• which is the environmental impact?• which is the environmental impact?

7. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
principal questions
• who has initiated this techn. change and why?
• how was this techn. change realised/directed?
• which is the environmental impact?• which is the environmental impact?
close co-operation between EU commission and European industry:
• programs Auto-Oil I (1992-1995) and Auto-Oil II (1996-2000) with European
Car and Oil Industry as main players
• the 1998 voluntary agreement between ACEA and EC with targets for 2008
• obviously all parties agreed to push diesel technology

8. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
Kyoto
protocol
diesel car penetration in world dominating markets.
+ 44 Mio diesel
cars in Europe
1996-2011
Cames & Helmers (2013)
All data are percentages, either annual new car registrations, or annual entire car fleet composition.

9. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
principal questions
• who has initiated this techn. change and why?
• how was this techn. change realised/directed? – on national level
• which is the environmental impact?• which is the environmental impact?
dieselization rate
versus direct
automotive
employment.
The coefficient of
determination R2
and regression line
have been calculated
excluding Sweden and
Germany.
Cames & Helmers (2013)

10. Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
principal questions
• who has initiated this techn. change and why?
• how was this techn. change realised/directed?
• which is the environmental impact?• which is the environmental impact?

11. 170
180
190
Reihe1 Reihe2
petrol cars EU
Diesel cars
EU
/kmg CO
2
particle filter in
a few diesel cars
particle filter
in most/all diesel cars
+ 76 g
CO2-
eq/km
EU 2
+ 38 g
CO2-
eq/km
EU 3
CO2 emission
time trend of
newly
registered
cars
additive
effect
of black
carbon
Sources: EU-15 figures 1995-1999 (European Commission, 2005); EU-27 figures (EEA, 2010a); Japan 1995-2006 figures recalculated by JAMA
(2008) data; Japan 2007-2010 figures recalculated by JAMA (2012) data
Cames & Helmers (2013)
120
130
140
150
160
1995 1997 1999 2001 2003 2005 2007 2009 2011
EU cars
in the EU
net advantage of
diesel cars:
4 g CO2/km ??

12. 2014 fine dust emitted by passing taxis was quantified at Frankfurt
main station in a measurement campaign
At every 10th diesel taxi , the filter was removed or did not work
• assumption: 10 % of all cars > 100,000 km with PF malfunctions
What is a diesel car emitting in reality ?
• assumption: 10 % of all cars > 100,000 km with PF malfunctions
100 mg soot/km + 76 g CO2-eq/km
• with 235,000 km driven roughly 5 % of all cars on street have PF
malfunctions
• in a diesel car pool with average direct CO2 emissions of 135 g/km
roughly 4 g CO2-eq/km have to be added
Diesel demand tripled over 20 years:
+ 2-10 g CO2/km extra expenses over supply chain

13. 170
180
190
Reihe1 Reihe2
petrol cars EU
Diesel cars
EU
/kmg CO
2
particle filter in
a few diesel cars
particle filter
in most/all diesel cars
+ 76 g
CO2-
eq/km
EU 2
+ 38 g
CO2-
eq/km
EU 3
filtermalfunctions
CO2 emission
time trend of
newly
registered
cars
additive
effect
of black
carbon
Sources: EU-15 figures 1995-1999 (European Commission, 2005); EU-27 figures (EEA, 2010a); Japan 1995-2006 figures recalculated by JAMA
(2008) data; Japan 2007-2010 figures recalculated by JAMA (2012) data
Cames & Helmers (2013)
120
130
140
150
160
1995 1997 1999 2001 2003 2005 2007 2009 2011
EU
filtermalfunctions
cars
in the EU
net advantage of
diesel cars:
4 g CO2/km ??

14. 2014 Frankfurt main station: At every 10th diesel taxi , the filter was
removed or did not work
What is a diesel car emitting in reality ? Over lifetime?
3/4 of 168 diesel cars had 1-4 engine malfunctions
some 700,000 used cars a year are exported from Germany to
eastern/southeastern Europe
emission aftertreatment technology removed just across the
border?!

15. • Diesel cars are essential to decrease CO2 emissions of passenger cars
some diesel car myths kept until today in Europe

16. • Diesel cars are essential to decrease CO2 emissions of passenger cars
170
180
190
petrol cars EU
CO2 emission time trend of newly registered cars
g CO2/km
some diesel car myths kept until today in Europe
100
110
120
130
140
150
160
170
1995 2000 2005 2010 2015
diesel cars EU
cars Japan
Sources EU 1995-2011: Cames & Helmers, 2013. EU 2012 + 2013: EEA 2014. Japan: JAMA 2015

17. • Diesel cars are essential to decrease CO2 emissions of passenger cars
modern downsized, charged petrol engines can compete, particularly hybrids
LPG fuelled petrol cars have slightly lower CO2 emissions
petrol cars driven with natural gas have less CO2 than diesels
not diesels but electric cars charged with renew. electricity are essential to
fundamentally decrease e.g. the carbon footprint of driving
some diesel car myths kept until today in Europe
fundamentally decrease e.g. the carbon footprint of driving
• “there was a continuous NOx emission reduction“
not in the past 20 years
a myth …
Euro 6

18. • Diesel cars are essential to decrease CO2 emissions of passenger cars
modern downsized, charged petrol engines can compete, particularly hybrids
LPG fuelled petrol cars have slightly lower CO2 emissions
petrol cars driven with natural gas have less CO2 than diesels
not diesels but electric cars charged with renew. electricity are essential to
fundamentally decrease e.g. the carbon footprint of driving
some diesel car myths kept until today in Europe
fundamentally decrease e.g. the carbon footprint of driving
• “there was a continuous NOx emission reduction“
not in the past 20 years
• „clean diesel“ cars will solve the problems
so far they are not on the streets
they will return to high emissions at higher mileage
a myth …
Euro 6

19. The “clean diesel”
V H P R S
urea solution
SCR-technology (selective
catalytic reduction) to reduce
NOx down to petrol/gasoline
engines emissions
V-Kat oxidation catalyst: oxidizing of NO 2 NO + O 2 NO
Helmers, 2009
V-Kat oxidation catalyst: oxidizing of NO 2 NO + O2 2 NO2
H-Kat urea decomposition to ammonia and isocyan-acid CO(NH2)2 NH3 + HNCO
P-Kat particle filter trap: deposition of soot und continuous oxidation
a) isocyan-acid generates active ammonia HNCO + H2O NH3 + CO2
b) NO2 burnes deposited soot (C) 2 NO2 + O2 + 2 C 2 NO + CO2
R-Kat excess NO and NH3 are being reduced: NO + NO2 + 2 NH3 2 N2 + 3 H2O
and 4 NO + O2 + 4 NH3 4 N2 + 6 H2O
S-Kat lock up catalyst: oxidation of remaining ammonia: 4NH3 + 3O2 2N2 + 6H2O

20. 40
50
60
%
Until the mid 1990s: Europe followed technology leaps initiated in the USA
That changed in the mid 1990s:
Diesel car penetration in Germany
+ 7 Mio diesel
cars in Germany
1996-2013
0
10
20
30
40
1990 1995 2000 2005 2010 2015
German fleet
German
registrations
30 % of the
German fleet
Sources: German Federal Motor Transport Authority, ICCT (2014) for UK data