If you were to draw up a list of how a Council could be more eco friendly and another list of how it could save money you would find many items that would appear on both – print less, save energy, don't keep sending staff off to conferences, reduce the amount of street lighting, don't replace humps when resurfacing roads, etc, etc, etc.
A paper from the excellent Localis think tank Giving the Green Light: Policy Ideas for a Model Environmentally Sustainable Council includes a section on staff travel. Instead of fleet cars it suggests car sharing. Also more working from home. It suggests phasing in green vehicles over time.