An ultra low emission vehicle (ULEV) includes any vehicle that emits less than 50g/km of carbon dioxide (CO2) at the tailpipe. They include:
- Pure or battery electric vehicles (EVs or BEVs)
- Plug-in hybrid vehicles (PHEVs)
A hybrid electric vehicle has an internal combustion engine and a small battery, which is charged when the driver brakes, known as regenerative braking. The battery power either assists the engine or drives the wheels entirely for a very short distance (usually less than a mile). This reduces fuel consumption and emissions, particularly in stop-start driving conditions.