West Sussex firm Crane Telecommunications teamed up with CitiCapital Fleet, which manages the fleet, to launch a driver education programme on the new tax.
A 'CO2 tax efficient' car option in each employee's choice bands was introduced in readiness for the changes.
The firm offers an 'emissions option' in each of the 10 choice bands. In band four, for example, drivers can choose an Audi A3 or Ford Mondeo, alongside the low CO2-emitting Volkswagen Passat 1.9 S TDI.
With the majority of drivers covering 30,000 business miles a year, and therefore heavily affected by next year's tax changes, Crane's HR director Russell Piper felt it was important drivers completely understood their position.
CitiCapital Fleet managing director Colin Tourick said the firm threatened to be the exception rather than the rule, because fleet decision-makers were still not reacting to the impending tax changes, which will be introduced in seven months' time.
He said: 'Too many companies are failing to grasp the issue now and will be scrambling to inform their drivers about the changes and put new policies in place at the 11th hour.'
Piper, who has been in charge of the project, said: 'We started looking at it about a year ago.
'Sales people are notoriously driven by what they drive and we had to get away from that culture.'
Over the past year Crane has sent out leaflets to its 50-strong sales force, given presentations and even set up a helpline for its drivers to educate them into taking more sensible, tax-friendly options.
A planned move to LPG-fuelled vehicles in three years' time could also cut fuel bills by £100,000.