Returnable Fuel/Returnless Fuel Comparison

Fuel is supplied at high pressure to the fuel injectors through a fuel injection supply manifold.

For vehicles without a returnless fuel system,
the fuel injection supply manifold is equipped with a fuel pressure regulator.
For vehicles with a mechanical returnless fuel system,
the fuel pressure regulator is integral to the [1][2][3]fuel pump module.

An inertia type fuel shutoff switch will cut power to the fuel pump in the event of an accident.

The fuel lines are metal with flexible connections.