The Single Common Powertrain Lubricant (SCPL) program is seeking to develop an all-season (arctic to desert), fuel-efficient, multi-functional powertrain fluid with extended drain capabilities. To evaluate candidate lubricants for the purpose of fuel consumption effects, a test cycle was developed using the GEP 6.5L(T) engine found in the HMMWV. Field data collected at Ft. Hood, TX was used to determine a set of speed, load and temperature points which could be reproduced consistently in test-cell operation. These points were condensed into a 14-mode cycle for use within the SCPL program. In addition to fresh condition oil, some lubricants were evaluated at end-of-life drain conditions to determine consumption effects over time. Results from the program indicated a significant fuel consumption benefit with lower viscosity lubricants when compared to current in-use military engine oils.