Watch the movie clip.
I turn the pump on, the hose jerks  and the fuel rises
in the line. The pump is located seven feet
above the can of paint thinner. That is with an open
injector. With a closed injector it takes just a second
or so longer. I double checked the current consumption
and it is exactly 3 amps at exactly 12 volts.
You are not going to beat this roller vane pump.

Dave Leonard is right about the return system.
I think it is the best for aircraft. It will
purge water, air and will start when hot.
I think the main driver for the non return
systems in cars is lower cost and evaporator
controls. Not a factor in an aircraft.

Paul Lamar

Hi Paul,
Wouldn't the amperage of concern be when the pump is running against
maximum system pressure? Dave M

The system pressure was 53 psi when the pump was drawing 3 amps at 12 volts.
The RX8 injectors are supposed to be running at 56 psi.
I can jack up the pressure and run the test again.
OK I did it. 62 psi 3.5 amps. Under cruise conditions
with the pressure controlled by the intake manifold the
current drain will be less.

BTW I would like to make a point about pressure regulators.
The RX8 fuel system pressure runs at 56 psi constantly regardless
of the intake manifold pressure. The computer mixture map is changed
to compensate for the higher relative pressures.

In my 555 EFI case the pulse width is only a function of
the mass airflow. However the amount of actual fuel injected is
both a function of the pulse width and the fuel pressure differential
between fuel pressure and intake manifold pressure. In the normal
case that is a one to one ratio as several people have pointed
out.

Paul Lamar