Evaluation of Future Fuels in a High Pressure Common Rail System - Part 1 Cummins XPI

Abstract : A series of fuels were tested on a bench stand designed and constructed for the Cummins XPI High Pressure Common Rail Fuel System. Included were ULSD, JP-8, an FT SPK, and Jet-A. Testing occurred at 60 and 93.3?C over a 400-hour NATO cycle. Fuel viscosity ranged from 1.90 to 0.65 cSt while lubricity wear-scar diameters were from 0.54 to 1.01mm (ASTM D5001) and 0.382 to 0.75mm (ASTM D6079). At the conclusion of each 400-hour test, components were evaluated for wear and overall system performance with the ULSD test acting as a baseline for comparison. Results showed the XPI system to be robust with regards to fuel lubricity and viscosity. Even under the harshest fuels, only small areas of concern were noted in the injectors. From these results, it is expected that a synthetic fuel such as that used could be successfully used, with proper lubricity additives, in military ground vehicle fuel blends.