For the first four months of this year, some 62% of all new cars ordered by customers of the contract hire and fleet management firm have had carbon emissions been below 140g/km, with 29% of them less than 120g/km. This is 12% higher than the same period last year as the pace of environmental change continues to accelerate.

The results compare with the first four months of 2010, when only 51% of new vehicles were below 140g/km, with 25% of those of less than 120g/km.

And the figures for the most recent sales month, April, show that the pace of change is continuing. Last month, 56% of all new vehicles ordered were less than 140g/km, compared with 46% for the same month last year, with 29% of them less than 120g/km compared to 25% last April.

Martin Brown, managing director of Fleet Alliance, said: 'We believe there are two main factors at work here. One is that corporate customers and their drivers are heeding the message that "green" equals lower costs as well as being more environmentally friendly.

'Drivers are selecting lower-emission vehicles because of the financial advantages which include lower BiK, National Insurance Contributions and VED, while companies are keen to promote greener vehicles to their staff as they mean lower tax charges for them, too.

'The second factor is that manufacturers have responded to legislative demands and are introducing far more choice in the sub-140 and sub-120 product sectors. There are now far more mainstream fleets cars falling into these categories and this is a trend that will only increase over time,' he said.

Fleet Alliance, which manages a fleet of over 9,000 vehicles on behalf of corporate customers, has seen emissions fall across the board but especially from the four brands that make up the Volkswagen Audi Group – Volkswagen, Audi, SEAT and Skoda – which between them accounted for 31% of the sales mix in the four months in question.

Ford and BMW are others that feature highly on the Fleet Alliance fleet and that have made significant attempts to lower carbon emissions across the board.

'The message that lower CO2 equals lower costs, lower fuel consumption and lower taxes is now hitting home and we have pushed it very hard with our clients. By making the right vehicle choices now, fleet decision makers can make cost savings running into several thousand pounds over the typical three-year-life of a vehicle,' added Brown.