Construction scale

A car is a big, big thing, often weighing over a tonne and a half. As a result, its construction has a significant footprint.

In particular, the construction of an electric car in the same range as a combustion engine emits more greenhouse gases. This is mainly due to the battery and its considerable weight.

Despite this, in France, over the lifetime of the car and therefore the number of kilometres travelled, choosing an electric car is clearly better for the climate.

Better, but far from bad! Today, it's no longer just a question of comparing technical solutions; it's a question of evaluating purchases in relation to climate objectives.

There is a wide range of data on vehicle manufacturing emissions. The first approach used the FNH-Carbone4 study, which proposes emission factors for the construction of 2 sizes of vehicle, distinguishing between internal combustion, electric and hybrid vehicles. Some of the data for vehicles seemed inconsistent, and from a methodological point of view we needed greater precision in calculating the footprint of electric vehicles.

This is why we are now adopting the following approach:

• For internal combustion vehicles, we use data from ADEME's Empreinte database, which gives a value of 4.5 kgCO2e/kg for the construction of a car. We apply this factor to the mass of the car to obtain the construction footprint, the mass being determined by the size of the vehicle.
• For electric vehicles, we calculate the footprint of the battery as a function of its capacity, then add the footprint of the construction of a combustion car of equivalent range.
• For hybrid vehicles, we use the same data as for electric vehicles (strong hypothesis, see note on the hybrid scale).