This SAE recommended practice provides standard dimensions for liquid fuel dispenser nozzle spouts and a system for differentiating between nozzles that dispense liquid fuel into vehicles with Spark Ignition (SI) Engines and Compression Ignition (CI) Engines for land vehicles. Current legal definitions only distinguish between “UNLEADED Fuel” and “All Other Types of Fuel.” These definitions are no longer valid. This document establishes a new set of definitions that have practical application to current automobile liquid fuel inlets and liquid fuel dispenser nozzle spouts.