What does "Wells-to-wheels" mean?

Wells-to-wheels emissions take into account the production and distribution of the fuel. It is a type of analysis that allows individuals to compare emissions over the entire life cycle of a vehicle —from the energy and materials used to power a vehicle, to the direct tailpipe emissions. This makes it more “apples-to-apples” when comparing to gas-powered rides. For example, although EVs produce no tailpipe emissions, the electricity used to power them does produce a certain amount of emissions, albeit notably less than a conventional car.

A wells-to-wheels analysis tracks emissions across two stages: well-to-pump and pump-to-wheels. The well-to-pump stage begins with the fuel feedstock recovery, followed by fuel production, and ends with the fuel available at the pump. The pump-to-wheels stage simply represents the vehicle’s operation.