Greenhouse Gas Rating
- This rating reflects vehicle tailpipe emissions of carbon dioxide (CO2), the most prevalent greenhouse gas (GHG). CO2 emissions typically constitute 99% of the tailpipe emissions of greenhouse gases.
- Vehicles that score a 10 are the cleanest
- Even though this rating only addresses what comes out of the tailpipe, it is important to note that the production of the fuel used to power your vehicle can also generate CO2. For example, activities associated with fuel production such as extracting (or getting) the raw materials, transporting them to a processing plant, and converting them into motor fuel, as well as distributing that fuel, can all produce GHG emissions These emissions are not included in this rating.
Rating Scales by Model Year (MY)
Methodology for model year 2012 and earlier
For model year 2012 and earlier, EPA quantified greenhouse gases as CO2e using emissions factors that were based on vehicle emission test results and fuel characteristics. Factoring in the global warming potential of each gas provides a vehicle's CO2 equivalent (CO2e) emissions. The CO2e emission factors that were used:
Table 1: Tailpipe CO2e Emissions Per Fuel Type | ||||
---|---|---|---|---|
CO2 | CH4 and N2O | |||
Fuel Type | Pounds/Gallon | Grams/Gallon | Grams/Mile | |
Gasoline | 19.59 | 8,8871 | 1.92 | |
Diesel | 22.44 | 10,1803 | 0.44 | |
E85 | 13.88 | 6,2955 | 4.06 | |
CNG | 15.50 | 7,0307 | 6.88 |