A new pintle injector has been designed and is being produced for IDI engine applications. It features improvements in the areas of heat shield requirements, internal volume and reciprocating mass. Reductions in spring requirements and shank diameter contribute to a smaller envelope. This permits optimization of injector installation and cylinder head design.This paper covers design details as compared to the current S-size nozzle. Test rig and computer simulations results show the improved hydraulic characteristics obtained. Engine temperature measurements are presented to substantiate installation without a heat shield. Engine test data is presented to illustrate performance improvements.