my USA old reasons for old FL washers are similar to the UK
Here with some items that are real super dirty; I have always tended to have the machine say 1/3 to 2/3 rds full, never chock full.
The reasons here are that one has a safety factor, one was too getting a better chance of cleaning; than a full load that is crammed real full .
*****ie I never really heard of:
"BUT it does not clean properly an half load of very soiled table clothes /kitchen towels. Half loads don't tumble cause there's too much water. "
****** until I came to this washing machine website.
Most of my experience is with FL washing is my older 1976 3 belt westy; which has an oval potato pulley that varies the wash speed between 52 to 62rpm. The only real effect of varying the load is the average rpm drops slightly with more load; the motor is just a dumb 1800 rpm AC induction motor. This rpm is such with its 22" diameter that items drop back into the wash water; they do not stay at the other radius
Here with say a weekends worth of dirty pants and tshirts to work on the car, roof or truck I typically wash these as one wash load; even if the machine is 1/3 full.
I do not "wait" and save up like greasy dirty items and then wash them 2 months or 3 months later "when the machine is full". There are several reason why. Stains set with time . I also would not want to add church white shirts in the same load as some greasy bluejeans and "hope" that it worked; I was not raised to roll the dice.
Thus often here in the USA some folks purposely do not do the "lets fill the washer to its max gambit" .
we often do not want stains to set, we often do not want to mix 30 dollar new white shirts with 50 cent thrift store bluejeans full of axle grease, we often do not want colors to bleed on white items.
The added "waste" of washing a 1/2 load cannot even be measured in our budgets, our machines often do what well at 1/2 loads too.
