Selection Criteria Cars


Topten selects the best automobiles with combustion engines regarding environmental soundness, which are available in Europe. They are displayed in seven different categories; from minis to vans. Basis for the researches are type-testing-specifications. Only cars for which we receive all the necessary technical specifications from the producersare can be considered for the list. More cars can be found on (French) or (German). In this wider list only automobiles with CO2 emissions of up to 180g/km are taken into consideration. The selection of Topten is based on the IFEU-study from 1997, which has regularly been amended with new scientific findings.

The minimum Eco points necessary for each category is listed below:

Category: Length of car (l): Eco Point:
Mini l < 3.6m 67.0
Small cars 3.6m ≤ l < 4.0m 64.5
Compacts 4.0m ≤ l < 4.4m 63.5
Middle class 4.4m ≤ l < 4.8m 54.0
Upper middle class 4.8m ≤ l < 5.0m 47.5
Vans with 5 seats 5.0m ≤ l 54.5
Vans with 6 or more seats 5.0m ≤ l 48.5

Ranking order

The selected cars are ranked according to the calculated Eco-points. Higher Eco-points show a better environmental compatibility. The order of presentation can be changed by clicking on the headings of the tables.

Fuel price (€ for 100'000 km)

The fuel costs are calculated for a driving performance of 100'000 km, based on the fuel price of 1.20 Euro per litre for petrol and 1.10 Euro per litre diesel. Real prices can differ considerably from these assumptions as tax systems vary a lot between countries.

Eco rating

The Eco rating is based on available and comparable data on cars in terms of polluting emissions and noise. It is a multi-criteria analysis which allows to compare cars according to their impact on the environment and human health, on the basis of current scientific knowledge. Four types of environmental impacts have been defined and then weighted in order to form a rating for each car:

60 Percents: Impact of CO2 and particles – green house effect
20 Percents: Impact on humans by traffic noise
15 Percents: Impact on human health by carcinogenic substances
5 Percents: Impact on nature

The ecological rating system for passenger cars which has been used since 1997 by ATE (Swiss association for traffic and environment) together with its sister organisations – the traffic associations of Germany and Austria - has been developed by the Institute for Energy and Environmental Research (IFEU) in Heidelberg, Germany, together with the German federal environmental agency, and it is based on the current knowledge of scientific data.

Eco stars

The Eco stars allow a quick judgement on the ecological compatibility of an automobile. For the maximum of 5 stars 63.5 ecopoints are needed.

63.5 points and more 5 stars
54.0 to 63.4 points 4 stars
47.5 to 53.9 points 3 stars
40.0 to 47.4 points 2 stars
below 40 points 1 star


Fuel with which the results of the rating have been calculated: petrol, diesel or natural gas.

Fuel (l or kg per 100 km)

Total fuel consumption, measured according to the New European Driving Cycle (NEDC ECE 15 EUDC) in litres for diesel or petrol and in kilogrammes for natural gas.

Particle filter

All diesel models shown on Topten have particle filters.

CO2 (g/km)

CO2 emitted for each driven kilometre.

Noise magnitude (dB(A))

Noise magnitude when driving.


The maximum number of seats is indicated (also for models with the possibility to vary the number).

Available in countries

Availability of models in European countries. "EU" means all countries of the European Union. "On demand" means, that producers could not indicate the availability and that consumers have to ask in their countries on their own. The country codes are according to ISO.



Producers, importers and wholesalers who think some of their models should be included in the Topten lists are kindly asked to inform the editors from Topten (info(at)

July 2012, Egli, Berger-Wey, Michel