•   The functional objectives for fuel injection systems can vary. All share the central task of supplying fuel to the combustion process, but it is a design decision how a particular system will be optimized. There are several competing objectives such as:

   •   power output
   •   fuel efficiency
   •   emissions performance
   •   ability to accommodate alternative fuels
   •   durability
   •   reliability
   •   driveability and smooth operation
   •   initial cost
   •   maintenance cost
   •   diagnostic capability
   •   range of environmental operation

     Certain combinations of these goals are conflicting, and it is impractical for a single engine control system to fully optimize all criteria simultaneously. In practice, automotive engineers strive to best satisfy a customer's needs competitively. The modern digital electronic fuel injection system is far more capable at optimizing these competing objectives than a carburetor.