What else is there to say about natural gas?  It's naturally produced by the earth, it's processed right here in America, and it's clean burning.  It's a perfect fit for medium duty and larger vehicle applications where you have larger fuel storage capacity.  Fleets all across the nation have been using CNG powered vehicles for several decades.  CNG means less energy dependency on foreign oil, less greenhouse gas emissions, and it's one of the most popular choices for cities and municipalities who want to reduce their carbon footprint.