This CNG conversion is certified, convenient and very economical. You are within 15 miles of a CNG filling station in either of the OKC or Tulsa metro areas, and not much further than that in the rural areas. This is BI-FUEL, so it still runs on unleaded gasoline (or compressed natural gas) at the push of a button.. View more vehicles and more photos at http://www.soonerfleetautosales.com; , Contact Stan @ 918-645-1768 or Mike @ 918-289-9591