How to estimate CO₂ emissions for ICE vehicles#

This tutorial explains how to configure the routing request to estimate the energy consumption of an internal combustion engine (ICE) vehicle, and how to convert this energy into CO₂ emissions.

Required fields in the routing request#

Ask for the estimation with the ENERGY_CONSUMPTION option, and describe the vehicle in routingVehicleProfile.routingEnergyVehicleFeature.

Set the following 4 fields of the ICE vehicle:

• dryWeight (kg): the vehicle's weight without consumables or passengers
• auxConsumption (W): the consumption of the auxiliary equipment
• scx (m²): the product of the vehicle's front area and its aerodynamic coefficient
• crr: the rolling resistance coefficient of the tyres, dimensionless, between 0 and 1 (0.007 in the example below)

Put the weight of the driver, the passengers and the load in payload (kg). Default value is 0. Only the sum of dryWeight and payload changes the result.

You also need to define these 2 parameters (which reflect a driving profile):

• maxAccel (m/s²): above 0.1
• maxDecel (m/s²): below -0.1

You can use 1.25 and -1.25 respectively.

Finally set these other parameters:

• engineEfficiency: depends on the type of fuel used by the engine:

• petrol and LPG: approximately 0.25
• diesel: approximately 0.3

• regenerativeBraking: false
• batCapacity: 1000 (kWh) Note: the vehicle has no battery, but a value above 0 is needed: without it, or with 0, the request answers 400. The value does not affect the result.

CO₂ emission conversion formula#

The estimation of CO₂ emission in kg is the value of the energyConsumption field in the response (in kWh) multiplied by G / K, where:

G = the emission factor (kg CO₂ / L), depending on the fuel:

• petrol: approximately 2.31 kg/L
• diesel: approximately 2.68 kg/L
• LPG: approximately 1.66 kg/L

K = the energy released by 1 litre of fuel (kWh/L):

• petrol: approximately 9 kWh/L
• diesel: approximately 10 kWh/L
• LPG: approximately 7 kWh/L

These are approximate values: where your country or your fuel supplier publishes its own factors, use them.

Therefore, to convert the energy consumption E (in kWh) into CO₂ emissions (in kg), multiply it by:

• petrol: 2.31 / 9 = 0.257
• diesel: 2.68 / 10 = 0.268
• LPG: 1.66 / 7 = 0.237

Example request for a diesel car#

Request#

{
  "routingMode": "MODE_VIAS",
  "outputLanguage": "fr",
  "destinations": [
    {
      "coordinateSat": {
        "lon": 2.243,
        "lat": 48.89661
      }
    },
    {
      "coordinateSat": {
        "lon": 2.649556640625001,
        "lat": 48.81703451637949
      }
    }
  ],
  "options": [
    "ENERGY_CONSUMPTION"
  ],
  "routingVehicleProfile": {
    "transportMode": "CAR",
    "routingEnergyVehicleFeature": {
      "dryWeight": 1000,
      "crr": 0.007,
      "scx": 0.7,
      "auxConsumption": 400,
      "payload": 150,
      "maxAccel": 1.25,
      "maxDecel": -1.25,
      "engineEfficiency": 0.3,
      "regenerativeBraking": false,
      "batCapacity": 1000
    }
  }
}

Response#

The energy is in the route's energyConsumption field (the other fields are left out):

{
  "routingRoutes": [
    {
      "length": 41991,
      "energyConsumption": 18.38025842359699
    }
  ]
}

CO₂ emission#

CO₂ emission = 18.38025842359699 × 0.268 = 4.9 kg