1 more thing.
In a wringer or twin tub washer, where the wash water never leaves the agitation tub, the soil is always in suspension. I believe an Automatic with a suds saver would yield even better performance because the water leaves the tub.
In an automatic, after the wash is over, the wash water is pumped to a separate tub. It then sits there stagnant for the rest of the wash cycle. During this time, I would imagine that oils and some lint would float to the top and sand would sink to the bottom. When the water is returned to the wash tub, the intake is just above the bottom. When the water level in the suds tub gets below the top of the suds intake, the wash water return stops, leaving a small amount of water in the bottom of the suds tub. I would believe that this remaining water would contain a higher amount of soil than the water returned to the machine.
I have very little experience with suds savers personally. I've only used one suds saver, and it is a Maytag. On the suds return cycle, the solenoid operated suds valve opens and the water is siphoned back into the tub as the timer runs. Once the water level in the tub equals that of the washer, the siphon stops. At the next timer increment, the washer starts to agitate with the suds valve open, sucking the water into the washer until the water level in the tub drops below the intake hose. When the timer is switched off or it advances to the end of the suds return cycle, the suds valve closes and the washer stops with a wash tub almost full of water.
It's old-school energy star,
Dave