8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 1/10
Energy Policy 36 (2008) 248–257
Influence of European passenger cars weight to exhaust CO2 emissions
Efthimios Zervasa,, Christos Lazaroub,1
aDepartment of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, GR-67100 Xanthi, GreecebInstitut d’Administration des Entreprises, Universite des Sciences et Technologies de Lille, 104, Avenue du Peuple Belge, F-59043 Lille Cedex, France
Received 11 May 2007; accepted 6 September 2007
Available online 22 October 2007
Abstract
The increase of atmospheric CO2 concentration influences climate changes. The road transport sector is one of the main anthropogenicsources of CO2 emissions in the European Union (EU). One of the main parameters influencing CO2 emissions from passenger cars (PCs)
is their weight, which increases during last years. For the same driving distance, heavier vehicles need more work than lighter ones,
because they have to move an extra weight, and thus more fuel is consumed and thus increased CO2 emissions. The weight control of new
PCs could be an efficient way to control their CO2 emissions. After an analysis of the EU new PCs market, their segment distribution and
their weight, some estimations for 2020 are presented. Based on this analysis, 13 base scenarios using several ways for the control of the
weight of future European new PCs are used to estimate their CO2 emissions and the benefit of each scenario. The results show that a
significant benefit on CO2 emissions could be achieved if the weight of each PC does not exceed an upper limit, especially if this limit is
quite low. The benefit obtained by limitations of weight is higher than the benefit obtained from the expected decreased future fuel
consumption. Similar results are obtained when the weight of new PCs does not exceed an upper limit within each segment, or when the
weight of each new PC decreases.
r 2007 Elsevier Ltd. All rights reserved.
Keywords: Carbon dioxide; Passenger cars; Tax incentives
1. Introduction
It is a known fact that the increase of atmospheric CO2
concentration influences climate changes. The transport
sector is one of the main anthropogenic sources of CO2
emissions. It accounted for 28% of total CO2 emissions in
Europe in 1998 (Internet site of Eurostat), while this
percentage was 23.4% for road transport in the same year.
In the last years, a willingness to control and decrease CO2
emissions can be seen through several internationalinitiatives, such as the Kyoto protocol (United Nations,
1992).
The transport sector is composed of ground, maritime
and air transport. The ground sector comprises rail and
vehicle transport, and the latter can be divided into the
transport of persons using passenger cars (PCs) and the
transport of goods using heavy-duty vehicles. The two
main categories of the current PCs are gasoline PCs and
diesel PCs, according to the type of fuel they consume. All
PCs do not emit the same amount of CO2. For the same
driving distance and power demand, diesel PCs emit less
CO2 compared with gasoline PCs.
Another CO2-influencing factor is weight. As for the
same driving distance higher-weight PCs need more work
than a lighter one, because they have to move an extra
weight, heavier PCs emit more CO2 than lighter PCs(Sullivan et al., 2004; Zervas, 2006, 2007). Other para-
meters also influence CO2 emissions, such as engine
displacement, fuel injection and combustion systems used,
etc. Newer engines have lower CO2 emissions than older
ones, as this parameter is taken into severe consideration
during the last years. However, using the same technology,
a heavier PC will still emit more CO2 than a lighter one.
For this reason, without neglecting technological improve-
ments, the control of PCs weight is one of the most
effective parameters for CO2 control.
ARTICLE IN PRESS
www.elsevier.com/locate/enpol
0301-4215/$ - see front matterr 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.enpol.2007.09.009
Corresponding author. Tel.: +30 2451079383.
E-mail address: [email protected] (E. Zervas).1Present address: Griponissioti 7, GR-32100 Livadia, Ukraine.
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 2/10
The European PC market shows several fluctuations
every year in relation to the total number of new PC
registrations, segment distribution and diesel penetration.
Based on the analysis of the past market evolution,
some estimations for the future (2020) European Union
(EU) market were presented in a previous work (Zervas,
2007). PC weight is one of the changing parameters in thelast years. The average weight of both gasoline and diesel
PC has shown a substantial increase (Internet site of
ACEA).
The present work evaluates the CO2 benefits obtained
if such a method is applied in the future. The current
and also the estimated future EU market of new PCs
(internet site of World Resources Institute (WRI)) are
reviewed and a number of estimations for the probable
future market are presented. Several plausible scenarios
for the future PC weight are constructed and the CO2
benefit is calculated for each of them. This control can be
achieved by several methods; some are presented in this
work.
2. Assumptions and methodology used
2.1. Data used
The statistical data used here are a compilation of data
presented in the internet sites of Eurostat, WRI, Interna-
tional Road Federation (IRF), Association of European
Automobile Manufactures (ACEA) and Committee of
French Automobile Manufactures (CCFA). The vehicles’
weight and CO2 emissions on the New European Driving
Cycle come from the German Federal Motoring Authority(KBA, 2003 version).
An analysis of the current passenger car market in the 15
European countries and its evolution since 1970 were
presented in a previous work (Zervas, 2007).The most
probable scenarios for the state of the EU market in 2020
were established and the CO2 emissions changes due to the
use of diesel instead of gasoline PC were calculated at
different percentages of diesel penetration.
2.2. Relationship between vehicle weight and CO 2 emissions
Using the KBA data, CO2 emissions of gasoline anddiesel PC can be presented as a function of vehicle weight
(Sullivan et al., 2004; Zervas, 2006, 2007). The equations
CO2 ¼ 0:1479 Weight 7:9 (1)
and
CO2 ¼ 0:1133 Weight 8:2 (2)
are valid in the case of gasoline and diesel PCs, with a
relative standard deviation of less than 10% (Zervas, 2006,
2007). However, an eventual replacement of gasoline PCs
by diesel versions is more likely to occur within the same
segment than within the same weight class. Accordingly,
two new lines are obtained using the average weight of
each segment:
CO2 ¼ 0:1702 Weightþ 6:7 (3)
and
CO2 ¼ 0:1398 Weight 11:0, (4)
for the gasoline and diesel PCs, respectively (Zervas, 2006,
2007). The average difference between the estimated CO2
emissions using the 2003 KBA file and the average weight
of each segment is very small: less than 1.8% in the case of
gasoline PCs and 2.8% in the case of diesel PCs. Eqs. (3)
and (4) are used in this work for the current fuel
consumption.
However, in the future, more severe emission standards
should require advanced emission control technologies, for
example the diesel particulate filter or DeNOx technolo-
gies, which would increase fuel consumption. On the other
hand, fuel efficiency is likely to be improved in the future
by improved vehicle aerodynamics, improved combustion,
decreased friction, etc. The work of Sullivan et al. (2004,and references therein) provides a list of technologies that
are expected to increase or decrease future fuel consump-
tion. In order to assess future gasoline and diesel fuel
consumption, the assumptions used here are
the diesel optimistic and pessimistic (DO, DP ) assump-
tions presume 0% and +5%, respectively, in diesel fuel
consumption change,
the gasoline optimistic and pessimistic (GO, GP )
assumptions presume 10% and 5%, respectively, in
gasoline fuel consumption change.
It is obvious that, if future diesel fuel consumption
decreases, the CO2 benefits estimated in this study will be
greater.
2.3. Analysis of the current European PCs market
In a previous work (Zervas, 2007), the values of 397.5
million inhabitants (estimated from Eurostat) for the
Western European population and of 18.0 million new
PCs registrations are used for the year 2020, giving a
ratio of 46.8 new PC registrations/1000 inhabitants for
the same year. In this work, the impact of diesel
penetration on CO2 emissions is calculated at different
future diesel penetrations. Two different diesel penetra-
tions are used in the present work: the current (in 2003)
and that estimated from Zervas (2007) if the average
annual increase of diesel penetration since 1980 is applied
to each country, with an upper limit of 80% (which
corresponds to a total diesel penetration of 63.7% in the 15
EU countries).
2.4. EU passenger car’s segment distribution
Another important parameter taken into account is the
PC segment. The European PC fleet is divided into 11
ARTICLE IN PRESS
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 249
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 3/10
segments (Zervas, 2006, 2007, Fig. 1). Fig. 1 shows the
percentage of new PC registrations as a function of the
average weight of each segment in 2003. The majority of
the EU average gasoline market corresponds to foursegments: Economic, Small Car, Lower Medium and
Upper Medium, while the majority of the diesel market
corresponds to three segments: Small Car, Lower
Medium and Upper Medium (Fig. 1). The most impor-
tant criterion for people to buy a PC of the Economic
segment is price. As Economic diesel PCs have usually a
much higher price than gasoline PCs, the percentage of the
diesel Economic segment is not very large. Also, the
percentages of Superior and Prestige segments are higher
in the case of gasoline PC, as buyers of these expensive
vehicles prefer the advantages of gasoline PC (like better
drivability and lower noise) and are not much concerned
by price. Fig. 1 shows that, in the case of gasoline PC,
the registrations percentage generally decreases with the
average segment weight. In the case of diesel PC, a
maximum value can be observed in the case of Lower
Medium segment.
The percentage of heavier segments is higher in the case
of diesel PCs: 8.4% and 2.9% of diesel PCs belong to the
SUV and 4 4 segments, respectively, versus only 2.2%
and 0.64% of the gasoline PC. The average weight of
gasoline and diesel PCs in the EU was, respectively, 1098
and 1306 kg in 2003. It must be noticed that significant
differences exist between each country: for example, in
2003, new PCs in Sweden and Finland were about 100 kg
heavier than the EU average (Zervas, 2007). The average
PC weight has increased constantly during the past years
(Internet site of ACEA), due to the incorporation of more
auxiliaries (air conditioning, enhanced safety auxiliaries,
more electric and electronic auxiliaries, etc.) and emission
post-treatment devices.
The segment distribution has not remained constant inthe last years. Figs. 2 and 3 show the historical evolution of
gasoline and diesel segment distribution since 1995 and the
estimations for these distributions until 2020.
ARTICLE IN PRESS
800 1200 1600 2000
Weight (Kg)
0.1
1.0
10.0
100.0
R e g i s t r a t i o n s (
% )
1
10
100
Gasoline
Diesel
ECO
ECO
SC
SC
LM
LM
UM
UM
SUP
SUV1
4x4-1 COMP
PRE
4x4-2
SUV2
SUP
SUV1
COMP
4x4-1
PRE 4x4-2
SUV2
Fig. 1. Segment percentage of new passenger car registrations in EU in
2003 as a function of the average weight of each segment. ECO: economic,
SC: small car, LM: lower medium, UP: upper medium, SUP: superior,
COMP: compact, PRE: prestige, SUV1: sport utility vehicleso4.5 m,
SUV2: sport utility vehicles 44.5m, 44-1: four wheel drive o4.5 m,
44-2: four wheel drive 44.5m.
2000 2010 2020
Year
0
20
40
R e g i s t r a t i o n s ( % )
0
2
4
0
5
10
15
R e g i s t r a t i o n
s ( % )
2000 2010 2020
SC
LM
UM
ECO
SUP
0
1
2PRE
COMP
SUV-1
SUV-2
4x4-1
4x4-2
Fig. 2. Gasoline PCs. Historical evolution of segment percentage of new
passenger car registrations in EU from 1995 to 2003 (blue symbols) and
estimations for the future segment distribution (red symbols).
2000 2010 2020
Year
0
20
40 R e g i s t r a t
i o n s ( % )
0
2
4
6
8
0
5
10 R e g i s t r a t i o n s ( % )
2000 2010 2020
SC
LM
UM
ECO
SUP
0
2
4
6PRE
COMP
SUV-1
SUV-2
4x4-1
4x4-2
Fig. 3. Diesel PCs. Historical evolution of segment percentage of new
passenger car registrations in EU from 1995 to 2003 (blue symbols) and
estimations for the future segment distribution (red symbols).
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 250
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 4/10
The future segment distributions are the average value of
two calculations:
the values calculated using the average annual change
from 1995 to 2003,
the values calculated using the extrapolation of the best
linear fit of the 1995–2003 percentages.
In the case of gasoline PCs, the percentage of some
segments should continue to increase: the Small Cars,
Economic and SUV -2 percentages should continue to
increase to reach about 45%, 16% and 1.5%, respectively.
Other segments, as Lower Medium, Upper Medium, Super-
ior and Compact should decrease to about 21%, 7%, 2.1%
and 0.3%, respectively. The percentages of Prestige and the
two 4 4 segments would remain practically unchanged.
This figure shows that the segment distribution of future
gasoline PCs should shift down to smaller vehicles.
In the case of diesel PCs, the Small Cars, Lower Medium,
SUV -1 and SUV -2 segments should continue to increase to
reach 23%, 41%, 6% and 5%, respectively, while the
Economic, Upper Medium, Superior and the two 4 4
segments should decrease to about 0.5%, 14%, 3.1%,
0.7% and 0.3%, respectively. This figure shows that the
diesel segment percentages should increase at the two
extremes (small and big vehicles), and decrease in the case
of intermediate vehicles.
2.5. Weight distribution of the current European new PCs
Fig. 4 shows the weight distribution of new diesel and
gasoline European PCs in 2003, for two weight ranges: 500
and 100 kg. It is clearly shown in this figure that, for
both weight ranges, the diesel weight distribution is
shifted to heavier PCs compared with the gasoline weight
distribution.
The majority (about 55%) of both gasoline and diesel
PC weight is found to be between 1000 and 1500kg;
however, the distribution is quite different in the case of lighter and heavier PCs. A total of 32% of gasoline PCs is
found to be lighter than 1000 kg against only 1.5% of diesel
PCs, while 30% of diesel PCs is found between 1500 and
2000 kg, against only 5% of gasoline PCs. When the weight
range narrows (100 kg), it is more evident that gasoline PCs
are mainly found around 1000 kg (from 900 to 1300 kg),
while diesel PCs present a first peak at the 1300–1700 kg
region and a second peak around 2200 kg. The percentage
of gasoline PCs heavier than 1600 kg is very low (less than
1% for each 100 kg weight range) compared with the diesel
ones.
Fig. 5 shows the weight distribution of each segment
when each segment is divided into four regions: the 0–25%,
the 25–50%, the 50–75% and the 75–100% of each
segment weight range (in 2003). Generally, the majority
of the new PC registrations of each segment occurred in the
25–50% segment weight range. The 0–25% region is
generally higher in the case of the gasoline PC, while the
two upper regions are higher in the case of the diesel PC.
This figure shows that once more, within each segment, the
gasoline PCs are generally shifted to lighter cars, while the
diesel PCs are shifted to heavier ones.
As expected, there is quite a high dispersion between
each segment weight distribution. For example, the SUV
and 44 segments are shifted to heavier PCs, while thedistribution of gasoline Small Cars is shifted to lighter
ones.
2.6. Estimation of the weight of the future European new
PCs
The future weight of a European PC is calculated as the
average value of two estimations (Fig. 6): the first is the
weight calculated using the estimated future segment
distribution shown in Figs. 2 and 3; the second is the
weight calculated after the extrapolation of the ACEA
average PC weight from 1995 to 2003. The extrapolationof ACEA data is rather pessimistic, as it leads to an
increase of 21.4% of the future (in 2020) PC weight. The
estimation of future PC weight from the segment distribu-
tion of Figs. 2 and 3 leads to a moderate increase of 2.2%.
The average value of these two extremes is used in this
work.
2.7. Scenarios for the future EU market of new PCs
Following the previous analysis, 13 base scenarios are
used in order to estimate the future changes of CO2
emissions (Table 1).
ARTICLE IN PRESS
1000 1500 2000 2500 3000
Weight (Kg)
0
10
20 P e r c e n t a g e
Gasoline
Diesel
0
40
80
<1000
1000-1500
1500-2000
2000-2500
2500-3000
Gasoline
Diesel
Fig. 4. Weight distribution of new diesel and gasoline PCs in 2003.
Percentage for two weight ranges of 100kg (lower curves) and 500 kg
(upper curves).
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 251
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 5/10
These scenarios take into account the following para-
meters:
First, the number of new PC registrations : Two values are
used here: the current registrations (in 2003), named
Current, and the value estimated from Zervas (2007) for
2020, which corresponds to 17 676 209 new PCs, named
Future.
The segment distribution: Two values are used here: the
current segment distribution (in 2003) named Current,
and the segment distribution estimated for 2020 (Figs. 2
and 3), named Future.
The fuel consumption: Five values are used here: current
fuel consumption (CFC ), GO, GP , DO and DP , as
defined previously.
Weight of PCs: Two values are used here: the current
one (in 2003, named Current) and the value estimated
for 2020 using the average curve of Fig. 6, named
Future.
Diesel penetration is an important factor for CO2
emission in the EU (Sullivan et al., 2004; Zervas, 2006,2007). For each base case scenario, the future diesel
percentage for each country is the value used in Zervas
(2007) from the extrapolation of the average annual
increase of diesel penetration from 1980 to 2003 with an
upper limit of 80%. The average future diesel percentage is
estimated to be 63.7% in the 15 member countries of the
EU (from Zervas, 2007).
For each one of the 13 base scenarios, four types of
possible approaches are examined in order to control the
weight of future PCs:
1. the weight of all PCs does not exceed an upper limit (the
values of 1000, 1200, 1400, 1600, 1800, 2000, 2200 and
2400 kg are studied),
2. a portion of a new PC does not exceed the previous
upper limit (the values of 30% and 50% are examined
using the same percentage for all segments),
3. all PCs of each segment do not exceed an upper limit
(the values of 25%, 50% and 75% of the segment weight
range are studied),
4. the weight of each PC decreases by a fixed value (the
values of 25, 50, 75 and 100 kg for each PC are studied).
In the case of the first type of possible approach of
future PC weight control, every PC with a weight higher
ARTICLE IN PRESS
0-25% 25-50% 50-75% 75-100%
Percentage Percentage
0
20
40
60
80
100
P e r c e n
t a g e
Gasoline
0-25% 25-50% 50-75% 75-100%
0
20
40
60
80
100
P e r c e n
t a g e
ECO
SC
LM
UM
COMP
SUP
PR
SUV-1
SUV-2
4x4-1
4x4-2
ECO
SC
LM
UM
COMP
SUP
PR
SUV-1
SUV-2
4x4-1
4x4-2
Diesel
Fig. 5. Weight distribution of each segment of new gasoline and diesel PCs in 2003. Percentage for a weight range of 0–25%, 25–50%, 50–75% and
75–100% of each segment weight range.
2000 2004 2008 2012 2016 2020
Year
1100
1200
1300
1400
1500
W e i g h t ( K g )
Segments
ACEA
Average
Fig. 6. Estimations of the future weight of new European PCs. Segments:
weight estimated using the segment distribution of Figs. 2 and 3 and the
current weight of each segment; ACEA: weight estimated using the
extrapolation of the ACEA average weight of PCs from 1995 to 2003;
Average: average value of the two previous values.
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 252
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 6/10
than the upper limit is considered to have a weight equalto this limit; the CO2 emissions of these PCs are calcu-
lated from Eqs. (1) and (2) for current fuel consumption
and using the appropriate coefficients for future fuel
consumption.
2.8. Possible ways for the weight control of new PCs
A major question is how the weight control of new PCs
can be achieved. We believe that there are two possible
routes to this. The first one is a decrease of weight
abandoning some luxury or secondary auxiliaries. Some
auxiliaries, as electrical windows, are considered asnecessary now; however, their weight can be significant.
A rapid calculation can give us some interesting results. Let
us consider that the devices for electrical windows have a
weight of 1 kg per vehicle window and let us consider that
the real windows are manual, so we decrease 2 kg of the
vehicle weight. Using Eqs. (3) and (4), the average decrease
of CO2 is 0.34 and 0.28 g/km for a gasoline and diesel PC of
1500kg. Considering a total mileage of 200,000 and
300,000 km for a gasoline and diesel PC and taking into
account the sales estimated for 2020, we obtain a gain of
about 131,000 ton of CO2 just from the weight reduction
of 1 kg.
The second possible route is the use of smaller andlighter cars, by decreasing the sales of big cars and
increasing the sales of smaller ones. This can be achieved
in several ways; we present only three here:
using tax incentives that decrease the prices of smaller
cars and increase the price of bigger ones. This system
will not have any financial charge because the taxes from
the bigger cars sales will fund the incentives for the
decrease of smaller taxes sales;
the application of taxes for the use of big cars which will
refund the users of smaller cars; and
the application of CO2 regulations.
The economic study of these tax incentives and of all
other parallel economic consequences on the automotive
industry and other linked industries, as refining for fuel
consumption, steel and other metal or plastic industries for
raw materials etc., is out of the scope of this work.
3. Results and discussion
3.1. Comparison of CO 2 emissions of each scenario
CO2 emissions present significant changes in the 13 base
scenarios studied (Fig. 7). If the current new PC registrations
ARTICLE IN PRESS
Table 1
Base scenarios used for the future weight of new PCs
Name New PC
registrations
Segment
distribution
PC weight Diesel
penetration
Fuel
consumption
1 Current-CSD-CW-CFC Current Current Current Current CFC
2 Current-CSD-FW-CFC Current Current Future Current CFC
3 Current-FSD-FW-CFC Current Future Future Current CFC
4 Future-FSD-CW-CFC Future Future Current Future CFC
5 Future-FSD-FW-CFC Future Future Future Future CFC
6 Future-FSD-CW-GODO Future Future Current Future GODO
7 Future-FSD-FW-GODO Future Future Future Future GODO
8 Future-FSD-CW-GODP Future Future Current Future GODP
9 Future-FSD-FW-GODP Future Future Future Future GODP
10 Future-FSD-CW-GPDO Future Future Current Future GPDO
11 Future-FSD-FW-GPDO Future Future Future Future GPDO
12 Future-FSD-CW-GPDP Future Future Current Future GPDP
13 Future-FSD-FW-GPDP Future Future Future Future GPDP
10 111 2 3 4 5 6 7 8 9 12 13
Scenario
80
100
120
140
160
C O 2 e m i s s i o n s ( B a s e = 1 0 0 )
Fig. 7. Estimations of the CO2 emissions change as a function of the
scenario studied, for the 13 base scenarios. Base: 100, for the scenario 1
(Current-CSD-CW-CFC).
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 253
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 7/10
are maintained, it can be seen that the change from current
to future weight, while keeping the current segment
distribution (scenario 2), will increase the CO2 emissions
by 8% compared with the current situation (scenario 1),
showing that the future increased PC weight will have a
negative influence on CO2 emissions. If the future segment
distribution is used, as in the case of scenario 3, CO2
emissions present a moderate increase of about 2%,
showing that the future segment distribution will help to
control CO2 emissions.
All scenarios using future new PC registrations show an
increase in CO2 emissions compared with scenario 1, due to
the higher number of new PC registrations. This increase
would be 30% in the case of scenario 4, using future
registrations and segment distribution but keeping the
current weight. If the future weight is used (scenario 5), the
increase reaches 40.6%. These two scenarios (4 and 5) use
current fuel consumption; if future fuel consumption is
used (scenarios 6–13) this increase is generally lower than
the increase in scenarios 4 and 5. The two GODO scenarios
(6 and 7) give a 5% lower increase because of the optimistic
fuel consumption. The two GODP scenarios (8 and 9) give
results similar to the two CFC scenarios (only 0.5–0.7%
lower). As diesel penetration is high in these scenarios, the
increased future diesel fuel consumption counterbalances
the benefits of the decreased gasoline future fuel consump-
tion. The two GPDO scenarios (10 and 11) give values
slightly (about 3%) higher than the two GODO scenarios
(6 and 7). This indicates that the evolution of future
gasoline fuel consumption plays a secondary role with
respect to this of future diesel fuel consumption, because of
the expected high future diesel penetration. Finally, the twoGPDP scenarios (13 and 14) show the highest CO2
emissions (increase of 132% and 142.5%), due to the
pessimistic future fuel consumption for both gasoline and
diesel PCs.
Scenarios 7, 9, 11 and 13 with future weight distribution
show an increase in CO2 emissions about 10% higher than
scenarios 6, 8, 10 and 12 with current weight distribution.
This is due to the increased PC weight in the four former
scenarios and shows the significant influence of this
parameter on future CO2 emissions.
3.2. Comparison of each scenario when the weight of each
PC does not exceed an upper weight limit
The CO2 benefit is estimated for different values of the
upper PC weight limit, in the case where all future new
PCs respect this limit (Fig. 8). Base scenario 1 (Current-
CSD-CW-CFC ) is found practically at the point 0% for
an upper limit of 2400kg, as very few PCs are above
this limit. The CO2 benefit in this scenario increases with
the decrease of the weight limit, more rapidly when the
weight is less than 1600 kg: it reaches 5% when the upper
limit reaches 1600 kg, 9% for a limit of 1400 kg, 16% for
1200 kg and 28% for 1000 kg. The three scenarios with
current new PC registrations (1, 2 and 3) tend to converge
to the same point of CO2 benefit for an upper limit of
1000 kg.
In all 13 scenarios, the CO2 benefit increases when the
upper weight limit decreases. Even the two future-CFC
scenarios (4 and 5), which estimate CO2 increases of about
30% and 40% compared with scenario 1 (Fig. 7), show a
CO2 benefit of about 10% for an upper limit of 1000 kg.
This fact demonstrates the significant CO2 benefit that can
be achieved when the weight of future new PCs decreases.
The middle and right parts of Fig. 8 show the CO2
benefit in the scenarios using future fuel consumption
(scenarios 6, 8, 10 and 12 for the middle part and 7, 9, 11
and 13 for the right part), compared with scenarios 4 and 5with current fuel consumption. In each part, the curves are
almost parallel and the differences on the CO2 benefits are
not higher than 5% for the same weight limit. This value is
very small compared with the benefits that can be obtained
from the upper weight limit decrease, showing once more
the effectiveness of the last method.
ARTICLE IN PRESS
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
-40
-20
0
20
40
C O 2
b e n e f i t ( % )
C-CSD-CW-CFC
C-CSD-FW-CFC
C-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-FW-CFC
-40
-20
0
20
40
C O 2 b e n e f i t ( % )
-40
-20
0
20
40
C O 2 b e n e f i t ( % )
F-FSD-CW-CFC
F-FSD-CW-GODO
F-FSD-CW-GODP
F-FSD-CW-GPDO
F-FSD-CW-GPDP
F-FSD-FW-CFC
F-FSD-FW-GODO
F-FSD-FW-GODP
F-FSD-FW-GPDO
F-FSD-FW-GPDP
Fig. 8. CO2 benefit as a function of the upper weight limit for all PCs, for the 13 scenarios used. (Left: scenarios 1–5 with current fuel consumption,
middle: scenarios 4 and 6–9 with current PC weight, right: scenarios 5 and 10–13 with future PC weight).
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 254
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 8/10
3.3. Comparison of each scenario when the weight of 50% or
30% of new PC does not exceed an upper weight limit
In the case where only 50% or 30% of all new PCs
respect an upper weight limit, the CO2 benefit is lower and
all the curves become more parallel to the x-axis, those of
30% more than those of 50% (Figs. 9 and 10). In bothcases (50% and 30%), the base scenario (Current-CSD-
CW-CFC ) is again found practically at the point 0% for an
upper limit of 2400 kg, as very few PCs are above this limit.
The CO2 benefit in all scenarios increases when the upper
weight limit decreases, but significantly less than the benefit
shown in Fig. 8.
The CO2 benefit in the first scenario is 2.5% for 50% and
1.5% for 30% of new PCs not exceeding the upper limit of
1600 kg (Fig. 11), against 5% in the case of 100% (Fig. 8).
These values become 14% and 8.5%, respectively, for the
upper limit of 1000 kg, against 28% in the case of 100%
(Fig. 11).
The CO2 benefit in all scenarios becomes lower when the
percentage of new PCs not exceeding an upper weight limit
becomes smaller (Fig. 11). These differences are rather
small when the upper weight limit is high, but increase
significantly when it decreases.
The middle and right parts of Figs. 9 and 10 show the
CO2 benefit in the scenarios using future fuel consumption
(scenarios 6, 8, 10 and 12 for the middle parts and 7, 9, 11
and 13 for the right parts), compared with scenarios 4 and5. The same tendencies as those shown in Fig. 8 can be
observed here. Even in the cases when only 50% or 30% of
new PCs do not exceed the upper weight limits, the
reduction of PC weight can be more effective in order to
decrease future CO2 emissions than the decrease of future
fuel consumption.
3.4. Comparison of each scenario when all PCs of each
segment do not exceed an upper weight
Fig. 12 shows the CO2 benefit when all new PCs of each
segment do not exceed an upper weight limit within this
segment (25%, 50%, 75% and 100% of the segment weight
range), as a function of this upper weight limit, for all
ARTICLE IN PRESS
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
C-CSD-CW-CFC
C-CSD-FW-CFC
C-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-CW-GODO
F-FSD-CW-GODP
F-FSD-CW-GPDO
F-FSD-CW-GPDP
F-FSD-FW-CFC
F-FSD-FW-GODO
F-FSD-FW-GODP
F-FSD-FW-GPDO
F-FSD-FW-GPDP
Fig. 9. CO2 benefit as a function of the upper weight limit if 50% of the new PC do not exceed this limit, for the 13 scenarios used (left: scenarios 1–5 with
current fuel consumption, middle: scenarios 4 and 6–9 with current PC weight, right: scenarios 5 and 10–13 with future PC weight).
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
1200 1600 2000 2400
Upper weight limit
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
-60
-40
-20
0
20
C O 2 b e n e f i t ( % )
C-CSD-CW-CFC
C-CSD-FW-CFC
C-FSD-CW-CFC
F-FSD-CW-CFC
F-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-CW-GODO
F-FSD-CW-GODP
F-FSD-CW-GPDO
F-FSD-CW-GPDP
F-FSD-FW-CFC
F-FSD-FW-GODO
F-FSD-FW-GODP
F-FSD-FW-GPDO
F-FSD-FW-GPDP
Fig. 10. CO2 benefit as a function of the upper weight limit if 30% of the new PC do not exceed this limit, for the 13 scenarios used (left: scenarios 1–5 with
current fuel consumption, middle: scenarios 4 and 6–9 with current PC weight, right: scenarios 5 and 10–13 with future PC weight).
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 255
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-emis… 9/10
scenarios used. The 100% upper limit corresponds to the
values shown in Fig. 7 (without weight limit). In the case of
the first scenario (Current-CSD-CW-CFC ), this figure
shows that the CO2 benefit is very small (0.7%) when the
upper limit is set at 75% of each segment range, because
the majority of PCs in the segment have a weight below this
limit. When the limit is set at 50%, the CO2 benefit is rather
high (4.5%) and reaches even higher values (18%) when it
is set at 25% of each segment weight range. Similar
tendencies are observed in all the other scenarios. The CO2
benefit at 75% limit is small, generally less than 2%, with
respect to no weight limit (100%). The CO2 benefit at 50%
limit is rather high (from 4% to 7%) while this at 25% limit
is significantly higher and reaches 17–24%.
All the different scenarios show the same order in CO2
benefit as shown in Figs. 8–11. The differences between
these scenarios slightly decrease as the weight limit
decreases. The middle and right parts of Fig. 12 show that
the difference between the scenarios using future fuel
consumption and those using current fuel consumption
remains between 1% and 4%.
3.5. Comparison of each scenario when the weight of each
passenger car decreases
Fig. 13 shows the CO2 benefit when the weight of all new
PCs decreases by a certain value, in function of this weight
decrease. The points with 0 kg decrease correspond to the
values shown in Fig. 7.
In the case of the first scenario (Current-CSD-CW-CFC ),
this figure shows that the CO2 benefit is about 2% when
this decrease is 25 kg, and increases linearly to reach 15%
for a weight decrease of 200 kg. Even in the case of a weight
decrease of 50 kg, the CO2 benefit is high enough, about
4%, and reaches 6% for a decrease of 75 kg. Similar linear
CO2 benefit curves are observed for all the other scenarios.
ARTICLE IN PRESS
1200 1600 2000 2400
Upper weight limit
-10
0
10
20
30C-CSD-CW-CFC 100%
C-CSD-CW-CFC 50%
C-CSD-CW-CFC 30%
C-CSD-FW-CFC 100%
C-CSD-FW-CFC 50%
C-CSD-FW-CFC 30%
C-FSD-FW-CFC 100%C-FSD-FW-CFC 50%
C-FSD-FW-CFC 30%
1200 1600 2000 2400
Upper weight limit
-40
-20
0
20
C O 2 b e n e f i t ( %
)
C O 2 b e n e f i t ( % )
F-FSD-CW-CFC 100%
F-FSD-CW-CFC 50%
F-FSD-CW-CFC 30%
F-FSD-FW-CFC 100%
F-FSD-FW-CFC 50%
F-FSD-FW-CFC 30%
Fig. 11. CO2 benefit as a function of the upper weight limit if 100%, 50% and 30% of new PC do not exceed this limit, for all scenarios used (only the
scenarios 1–5 using the current fuel consumption are shown).
0 100
Upper limit within each segment (%)
-40
-20
0
20
C O 2 b e n e f i t ( % )
-40
-20
0
20
C O 2 b e n e f i t ( % )
-40
-60
-20
0
20
C O 2 b e n e f i t ( % )
C-CSD-CW-CFC
C-CSD-FW-CFC
C-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-CW-GODO
C-FSD-CW-GODP
F-FSD-CW-GPDO
F-FSD-CW-GPDP
F-FSD-FW-CFC
F-FSD-FW-GODO
C-FSD-FW-GODP
F-FSD-FW-GPDO
F-FSD-FW-GPDP
80604020 0 100
Upper limit within each segment (%)
80604020 0 100
Upper limit within each segment (%)
80604020
Fig. 12. CO2 benefit if all new PCs of each segment do not exceed an upper weight limit within this segment (25%, 50%, 75% and 100% of the segment
weight range), as a function of this upper weight limit, for all scenarios used.
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 256
8/14/2019 28 - 2008_Energy-Policy_Zervas-E._Influence-of-European-passenger-cars-weight-to-exhaust-CO2-emissions.pdf
http://slidepdf.com/reader/full/28-2008energy-policyzervas-einfluence-of-european-passenger-cars-weight-to-exhaust-co2-em… 10/10
All the different scenarios show the same order in CO2
benefit as shown in Figs. 8–12. The differences between
these scenarios remain constant with the weight decrease,
as all curves are parallel. The middle and right parts of
Fig. 13 show that the difference between the scenarios
using the future FC and those using the current FC
remains between 1% and 4% (as observed in Fig. 12).
4. Conclusions
Considerable reductions in CO2 emissions can be
obtained if the weight of future (2020) new PCs is
controlled. In order to evaluate potential CO2 benefits,
the EU new PC market is analyzed and several parameters,
such as new PC registrations, segment distribution, weightdistribution and fuel consumption, are used to establish 13
base scenarios and, for each scenario, examine four ways of
new PC weight control.
The main results of this study show that the expected
increase in weight of future EU new PCs will have a negative
effect on CO2 emissions. The future number of new PC
registrations, also expected to increase, should also have a
negative effect. The effect of future fuel consumption will
depend on the changes in gasoline and diesel fuel consump-
tion and the future diesel penetration in the EU market.
When the weight of each new PC does not exceed an
upper limit, a significant CO2
benefit is observed, especially
when this limit is low. This benefit is higher when all future
new PCs respect this limit and decreases when only a part
of the fleet respects it. The benefit obtained by limitations
of weight is higher than the benefit obtained from the
expected decreased future fuel consumption. Similar results
are obtained when the weight of new PCs does not exceed
an upper limit within each segment, or when the weight of
each new PC decreases.
References
Internet site of the Association of European Automobile Manufactures
(ACEA) /www.acea.beS.
Internet site of the Comity of French Automobile Manufactures (CCFA)
/www.ccfa.frS.
Internet site of Eurostat /www.europa.eu.int/comm/eurostat/S.Internet site of the German Federal Motoring Authority (KBA), 2003
/www.kba.deS.
Internet site of the International Road Federation /www.irfnet.orgS.
Internet site of the World Resources Institute /www.earthtrends.wri.
orgS.
Sullivan, J.L., Baker, R.E., Boyer, B.A., Hammerle, R.H., Kenney, T.E.,
Muniz, L., Wallington, T.J., 2004. CO2 emission benefit of diesel
(versus gasoline) powered vehicles. Environmental Science and
Technology 38 (12), 3217–3223.
United Nations Framework Convention on Climate Change, United
Nations, Kyoto, Japan, 1992 /http://unfccc.int/essential_background/
kyoto_protocol/background/items/1351.phpS.
Zervas, E., 2006. CO2 benefit from the increasing percentage of diesel
passenger cars. Case of Ireland. Energy Policy 34 (17), 2848–2857.
Zervas, E., 2007. European CO2 benefit from the increasing percentage of diesel passenger cars, SAE 2007-01-1947.
ARTICLE IN PRESS
0 120 160 200
Weight decrease of each vehicle (Kg)
-40
-20
0
20
40
C O 2 b
e n e f i t ( % )
-40
-20
0
20
40
C O 2 b e n e f i t ( % )
-40
-20
0
20
40
C O 2 b e n e f i t ( % )
C-CSD-CW-CFC
C-CSD-FW-CFC
C-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-FW-CFC
F-FSD-CW-CFC
F-FSD-CW-GODO
C-FSD-CW-GODP
F-FSD-CW-GPDO
F-FSD-CW-GPDP
F-FSD-FW-CFC
F-FSD-FW-GODO
C-FSD-FW-GODP
F-FSD-FW-GPDO
F-FSD-FW-GPDP
8040 0 120 160 200
Weight decrease of each vehicle (Kg)
8040 0 120 160 200
Weight decrease of each vehicle (Kg)
8040
Fig. 13. CO2 benefit if the weight of all new PCs decreases by a certain value as a function of this value, for all scenarios used.
E. Zervas, C. Lazarou / Energy Policy 36 (2008) 248–257 257