Tuk-tuk‘ at the University of Moratuwa burns a fuel that provides completely negligible emissions. By taking the use of gas is cleaner, and a transition from diesel and gasoline to biogas produces less greenhouse gases.
More tuk-tuks in Sri-Lanka will now be running on fuel derived from food waste.
Source: http://rickshawchallenge.com/blog/2009/12/biogas-fuel-for-tuk-tuks-in-sri-lanka/
3 Wheeled Cheese 
Great work