The two D1-branded TX1 black hackney cabs will be running on a 5% biodiesel blend.
D1 has branded the cabs with the D1 logo and a design based on the leaves of the jatropha tree, D1’s alternative raw material for producing biodiesel.
Jatropha is an oilseed tree that grows in tropical and sub-tropical regions and produces high yields of inedible vegetable oil that can be refined into high-quality biodiesel.
Unlike food oils used to make biodiesel, such as soya and palm, jatropha can grow on poor quality land that is unsuitable for food crops.
It is claimed that growing jatropha to make biodiesel will not destroy rainforest or replace food crops.
Elliott Mannis, chief executive of D1 Oils, said: "It’s important that we encourage more drivers to use biodiesel and more petrol stations to sell it.
"Branding the taxis with our logo is a great way to advertise D1 to key audiences, particularly city investors, but it’s also a way for a company like ours to ensure that two more vehicles on London streets are running on fuel that is less damaging in terms of air quality and carbon emissions."