Borax will soften your water, which allows the detergent to work better allowing much less detergent.
It will also help a lot if you have well water because our water from the laundry smells really bad and the clothes were clean, but smelled bad too. Then the washer drains into a pit in the floor and gets pumped out with a sump, so that water sitting stunk up the whole basement, which then permeated up the steps and through the ductwork to the upstairs. 1/4 cup in the laundry and now the clothes are clean, clean smelling, and the basement doesn't smell either.