The company started trialling electric power in 2008, introducing 19 vehicles across London, Paris and Los Angeles. These latest 24 vehicles, including factory builds and electric conversions, will add to the Los Angeles fleet, with the rest split between New York, Chicago and Memphis.

It forms part of an electric vehicle trial, examining how different models suit different delivery routes. The fleet will also gain an unconfirmed number of new hybrid vehicles in a bid to bring down its company-wide emissions.

Dennis Beal, vice president of Global Vehicles at FedEx Express, said: ‘We are using efficient technologies that are readily available now, while investing in innovative technologies that we hope and believe can be vehicle workhorses for the future.’