Whitbread, which runs a 950-strong fleet, has introduced initiatives such as home-based working and mileage reimbursement, with employees receiving a £2 a month bonus for every mile per gallon their vehicles achieve above 40mpg. They lose £2 a month for every mile under 40 mpg.
Such incentives have meant that fuel consumption has surged from 34mpg to more than 40mpg. Whitbread expects the economy mark to hit 50 after introducing more economical vehicles.
Whitbread's green fleet initiatives have helped the group slash CO2 emissions by 1,600 tonnes, rewarded with three stars under the Government-backed Motorvate initiative.
The brewery has also reduced its fleet from 2,750 to 950 over the last five years, with more than 60% of its fleet now running on diesel.
Laura Hartley, one of Whitbread's employees involved in the scheme, said: 'I was really pleased when I found out that Whitbread was actively trying to do something about the environment and the fact that I can reduce my costs simply by choosing a more fuel-efficient car is great.'
The group is pushing even further ahead with its green policy after taking delivery of three petrol-electric hybrid vehicles.
Whitbread chose to introduce the Honda Civic IMAs in a bid to reduce the company's impact on the environment even further. Fleet manager Nigel Trotman said: 'Whitbread takes its environmental responsibilities seriously and we were keen to offer employees a green company car option which reflects our commitments to the Motorvate scheme and the company's wider environmental policies.
'We recognise that many of our employees spend a considerable amount of time in their cars and that its choice is important to them, so offering a wide range is one way of rewarding these people at the same time as making progress on our environmental targets.'
The brewery has ordered a fourth Honda Civic IMA as part of its environmental pledge.