Compressed natural gas (CNG) vehicles have been utilized in fleet applications in the United States for decades. However, vehicles capable of running on both gasoline and CNG are uncommon, with very few applications intending to use bio methane instead of CNG. This paper discusses the conversion of a production vehicle running on gasoline, CNG, and bio methane, the product of upgraded biogas. The technology used in this application allows the vehicle to switch instantaneously between the liquid and gaseous fuels without affecting drivability. The CNG tank is mounted in the bed of the truck and is plumbed to the engine bay, where the fuel is injected into the engine via natural gas fuel injectors. The vehicle is tested for exhaust gas emissions (CO, CH4 , CO2 , NOx , and HC). This article will present a detailed description of the bi-fuel vehicle, the CNG fuel system, the test procedures followed, the aforementioned test data, analysis of the test results, and a comparison of the results for CNG and gasoline as fuels