An environmentally friendly black cab is taking to the streets of London for the first time.
The car drives on both a diesel and an electric engine
Makers say the taxi can run on both diesel and electrical power which means reductions in the amount of pollution current models emit by up to 90%.
Cabbies who drive the new vehicles could make major fuels savings with no loss in performance, designers say.
And they claim the new 'Hybrid Electric Vehicle' can go further and accelerate faster than the current models.
A built-in computer knows when to switch between power sources depending on the demands made by the driver.
The taxi has been developed by engine designer Azure Dynamics and London Taxis International with support from the Energy Saving Trust and the Department for Transport.
Commercial vehicles only account for 12% of all miles travelled but they produce 25% of 'ground level' pollutants, government-commissioned research suggests.
Transport Minister David Jamieson said greener black cabs were "good news" for Londoners and he hoped cabbies would embrace the new technology:
"London's black cabs are widely recognised as a symbol of one of the greatest capital cities in the world," he said
"This advanced hybrid technology solution is a step in the right direction to create a cleaner and greener London."