Two 1998 Ford E350 Cutaway buses with 5.4L V8 CNG engines were acquired for testing and modification.  One vehicle was converted to a 30% HCNG blend using conversion technology developed by Collier Technologies.  The conversion included the addition of a supercharger and exhaust gas recirculation.  Chassis-dynamometer and road tests were performed on both vehicles to compare the performance and emissions effects.  

Testing showed reductions in oxides of nitrogen (NO_x) and carbon monoxide (CO) of 85 % and 60%, respectively for the HCNG vehicle compared to the CNG vehicle. There was no penalty in performance using the HCNG fuel due to the supercharger, however, fuel consumption increased by 6%.  This fuel consumption increase equates to a 19% increase on an energy equivalent basis, resulting in a comparable range reduction.

 This project demonstrated that with minor modifications to a CNG vehicle, a 30% Hydrogen, 70% CNG blend fuel can be used to reduce NO_x emissions with minimal effects on performance.  However, additional optimization and calibration will be necessary in order to maintain driving range, or alternatively performance can be sacrificed for better fuel economy.