Estimated car consumption

While we have worked on proposals for average consumption, the ideal situation, given the impact of this data, is for users to enter their own actual consumption, averaged over their usage.

To arrive at our proposals for individual cars, we cross-referenced two sources of data:

• Average fuel consumption data for petrol and diesel vehicles, supplied by ADEME (the French Environment and Energy Management Agency)
• Data on 'best consumption' by size and fuel, provided by this CAROOM article:

We were unable to find any other source for average fuel consumption by vehicle type. The CAROOM article gives the best performance figures by vehicle:

On the other hand, we have the data provided by ADEME, which gives average consumption figures of 6.8 L/100km for petrol and 5 L/100km for diesel. It's clear that the average fuel consumption calculated using CAROOM data (4.85 L/100km and 3.78 L/100km) is much lower than that calculated by ADEME, which means that the average fuel consumption is much higher aDEME's figures, these are the most efficient cars.

We have therefore reworked the figures using a ratio (average consumption / average efficient consumption) to update the average consumption per vehicle: For example, for a petrol city car, we obtain a figure of 7.11 L/100km using the following formula: 5.07 / 4.85 * 6.8.

• Corrected averages (used in NGC):

  E5 or E10	Diesel	% circulation
  Small	7.11	4.83	25.29%
  Medium	6.59	4.96	10.30%
  Sedan	6.59	4.96	49.81%
  SUV	7.13	5.48	14.60%
  Weighted average	6.80	5.00

For light commercial vehicles, we have used this source:

• Consumption of light commercial vehicles

We have noted that the fuel consumption of a petrol city car is higher than that of a saloon car, which seems counter-intuitive, but we have no other sources for the moment.

Finally, to obtain the fuel consumption of vehicles running on E85 petrol, we have applied an overconsumption of 25% compared with petrol vehicles, a figure that seems to be widely accepted.

Similarly, to obtain the fuel consumption of vehicles running on LPG, we have applied an overconsumption of 15% compared with petrol vehicles, except for LPG, for which we already have the data.