This paper describes the results of a study that is being performed to quantify the emissions benefits and performance characteristics of 20% biodiesel blends (B20) in diesel locomotives representative of the current NJ TRANSIT diesel locomotive fleet. Testing is being performed with #2 diesel summer blend, #2 diesel winter blend, ultralow sulfur diesel (ULSD) summer blend, ULSD winter blend and B20 blends with each of these fuels. Tests are performed on two different diesel locomotive engines to determine the differences in performance and emissions between newer and older locomotive engines when operating on biodiesel blends. The first phase of the project, which is described herein, is performed by operating both diesel engines statically (using a load bank) over the full test matrix of 8 fuels. During this phase, brake specific exhaust emissions and fuel consumption are computed for each fuel blend using the line-haul and switcher duty cycles as outlined in the CFR Part 40 Title 92 Federal Test Procedure. To accurately quantify the exhaust emissions, measurements are made using a Sensors SEMTECH-D mobile emissions analyzer to measure CO, CO2, NO2, NO, O2, and total unburned hydrocarbons (HCs), along with a Wager 6500RR Railroad Opacity Meter.