I had the same question and I may have answered it. Just how important are those fabric care label dryer temp recommendations?
We have a 1982 Kenmore Heavy Duty Plus 110.87170800 gas dryer(small door). Dryer only has 1 temp and air.
It has 2 automatic cycles, Cotton/Sturdy and Permanent Press.
The only difference between the 2 cycles is the cooldown time. It is 5 mins. on Cotton/Sturdy and 10 mins. on Permanent Press.
Also has Timed Cycle with 10 min. cooldown(includes Touch-Up cycle) plus 25 min.Air Cycle. In the instructions they recommend using the automatic cycles for most drying and the timed cycle for damp drying,knits and also if the dryer is located where the temp is below 45 degrees because the automatic cycle may not turn the dryer off.
Here are the suggested dry times:
Knits-Delicates 15-30 mins.
Permanent Press 30-45 mins.
Denims-Work Clothes 45-65 mins.
Towels 45-60 mins.
Mixed Cottons 35-50 mins.
I assume that the 15-30 min. timed setting recommendation for Knits-Delicates simulates low heat,(even though it really isn't) by limiting the heat time(as Tomturbomatic said).
Also from what I understand the adjustable replacement thermostats are intended for multiple applications and the markings (ABCDE)correspond to the particular OEM temp (this dryer is 150 degrees)and they are not intended to be set higher or lower then the recommended OEM temp. I will be replacing all thermostats as part of preventative maintenance soon.