An injection system for an internal combustion engine

Described herein is a fuel-injection system (1, 1', 1'') for an internal-combustion engine (2), of the type provided with compressor means (4) for making available the fuel at a high pressure to an storage volume (7), and a plurality of injectors (8, 8") fluidically connected to the storage volume (7) for taking in the fuel from the storage volume (7) and injecting it into respective combustion chambers (12) of the engine (2); the compressor means (4) advantageously generate at least two distinct delivery lines (14), which are connected to respective distinct fractions (16) of said storage volume (7).