It's not just for the EFI - look at the previous poster's list. Electric fans pull a lot (my Contour fans draw 40 amps on high). Fuel pumps. Headlights and accessories. Etc. Etc. All the little things that pull an amp here and two amps there. Adds up.
Agreed. At idle. I'm making about 12.3 volts per the Holley "dash" sometimes as low as 11.9. The 55 amp Powermaster isn't cutting it.
