ULEVs are currently defined as having less than 75 grams of CO2 per kilometre (g/km) from the tail pipe. Pure electric vehicles, and other plug in electric vehicles when driving in the electric mode, produce no tailpipe CO2 or pollution, are cheaper to run than conventional vehicles and can attract financial incentives, for example ULEVsare currently eligible for the 100% cleaner vehicle discount when entering the London’s Congestion Charging Zone.