Electric cars now sold in Britain are projected to produce less than half the lifecycle greenhouse-gas emissions of petrol and diesel cars, according to a study of the country's vehicle fleet. Researchers at Imperial College London estimate 88 grams of carbon-dioxide equivalent per kilometre for current battery-electric vehicles, compared with 254 to 270 grams for conventional cars. The calculation includes manufacturing and energy use across a vehicle's life, so it tests whether lower emissions while driving outweigh the extra emissions from making a battery.
A car's lifetime emissions depend on how far it travels and how long it remains on the road. Manufacturing emissions are spread over fewer kilometres when a vehicle is used lightly or retired early, weakening its lifecycle result. This has been a particular uncertainty for electric cars because the oldest models represent a small, rapidly changing part of the fleet.
Daniel Mehlig and Iain Staffell used records covering every electric vehicle in Britain to compare annual mileage and survival with conventional and hybrid cars. They trained a transformer neural network, a model that learns patterns across sequences of records, to project mileage and lifetime as newer electric-car cohorts age. The model therefore estimates the full lives of vehicles that have not yet been on the road long enough to observe directly.
The earliest battery-electric cars were driven less and did not remain in service as long as conventional cars, but the study still found lower lifecycle emissions for them. More recent cohorts have narrowed both gaps. If those trends continue, battery-electric cars bought in 2026 will match conventional cars in annual mileage and lifetime, the researchers report. The comparison is specific to British driving patterns, electricity supply and vehicle conditions.