Well-to-Wheel / Well-to-Wake

WTW refers to a specific scope or boundary used for measuring GHG emissions from transportation activities. It encompasses the full life cycle of the fuel used by a vehicle, from:

● Well-to-tank (WTT): the extraction, production, refining, and distribution of the fuel (e.g., gasoline, diesel, electricity for electric vehicles).

● Tank-to-wheel or Tank-to-wake (TTW): the combustion of the fuel in the vehicle's engine and the resulting emissions released at the tailpipe.
Therefore, WTW emissions essentially capture the total climate impact of a vehicle's fuel use, going beyond just the immediate exhaust emissions at the tailpipe.