Fuel evaporation in the fuel tank is reduced by adjusting the fuel amount (fuel pressure) ejected from the fuel pump and preventing fuel warmed in the engine compartment from returning.
The returnless fuel system consists of the following parts:
| Part name | Reference |
| Fuel filter (low-pressure) | |
| Fuel filter (high-pressure) |
|
| Pressure regulator |
|
| Fuel pump |
Fuel in the fuel tank is pumped out through the fuel filter (low-pressure) by the fuel pump, filtered by the fuel filter (high-pressure), and then regulated to a specified pressure by the pressure regulator. The regulated fuel is sent to the high pressure fuel pump, and unnecessary regulated fuel is returned from the pressure regulator to the fuel tank.
