Whirlpool Sensor Systems
Would actually surprise me if the US WP soil sensors would not have the ability to override default temperatures.
It's basicly a given thing that a sensor cycle in the EU can alter wash temperature depending on sensing.
Depending on manufacturer, model and cycle, temps range from 40C to 75C (104F to 167F), with different degrees of granular behaviour (some only have 2 temp levels, some are actually close to infinite to my knwoledge) and ways of reacting to certain sensing scenarios (some default to max temp just when they need to run a prewash, the infinite system that I think I read about somewhere actually heats the mainwash as long as there is a change in the sensor readout).
Some manufacturers even alter final rinse temps depending on load size (big loads retain more energy and thus dry well at lower temps while smaller loads retain less heat and thus need more heat to dry).
The move to 105F default mainwashes seems just logical on a 120F hot water supply that has to be instantly at 120F for test cycles.
If you run one or two prewashes, under test conditions, the main wash fill shouldn't drop below 105F. Thus barely any, if any at all, heating is required.
With high detergent concentrations, lots of enzymes and lots of time, that should work perfectly.
I however think that somewhere in the sensor logic of WP machines, there is a path that raises the temperature automaticly to high temp levels.
I saw that some models have manuals that have "Light to Moderate", "Heavy" and "Baked on" listed next to usages. Thus, the machine senses at least 3 different soil conditions.
"Baked on" appears to work more like an extended soak mainwash as sometimes water usage is slightly lower compared to "Heavy" while cycle times appear mostly equal IIRC. Would make sense as to penetrate into crusty stuff. I suppose that is sensed via the soil sensor during main wash. I would guess that the machine waits for the detergent to dissolve, then takes a baseline turbidity reading. As baked on stuff won't come of during the short prewashes, it will now slowly dissolve and thus step by step increase turbidity during the main wash even though the prewashes showed little contamination. Thus, it decides stuff was baked on.
Heavy probably just uses lots of prewashes with a shorter and probably slightly hotter main wash. Logic being that "Heavy" just means lots of soil. As most just dried and not baked on stuff can be quickly rinsed of with pure water, the bigger amount of soil that starts that scenario is dissolved in the prewash stage. So if there is huge influx of soil during the prewashes, the "Heavy" path is chosen, with lots of water changes and a hot main wash to better combat high fat content soils.
