The development of a rational evaluation method that can be applied to greases subject to low temperature service is attempted using a two level approach. The greases are evaluated as to their expected performance based on criteria that are currently believed to be important. The actual performance of the greases is then assessed in service on a railway hauling iron ore in northern Sweden and Norway under severe conditions of low temperatures and heavy duty demands. The relevance of the expected criteria in predicting actual performance will be used to establish a weighting system for each criteria to develop an overall performance number that can be used for rational selection of greases for low temperature service. Several methods of evaluating the performance criteria are discussed along with their advantages and drawbacks. The overall plan for developing the performance number is presented. Present progress is reported along with an estimate of future developments and their expected availability and impact on the overall plan.