A fleet of 200 council vehicles has been switched to an environmentally-friendly fuel.
Darlington Borough Council's diesel engine vehicles now use bio-diesel which is a blend of mineral oil, ultra low sulphur diesel and plant oils.
The fuel costs the same as diesel but helps reduce emissions of greenhouse gases and other pollutants.
It also provides more miles to the gallon and the engines did not have to be altered to use the new greener fuel.
Reduce impact
Stephen Harker, Darlington Council's cabinet member for consumer and environmental services, said: "The council is committed to addressing the issues of climate change and greenhouse gas emissions.
"Changing to this type of fuel is just one of the many ways the council is working to protect the environment for future generations."
The environmentally-friendly move coincides with the launch of the council's Declaration on Climate Change.
Its aim is to develop a range of ideas to reduce greenhouse gas emissions on a regional level.