[mrcartmeneses]

Conversely my t-shirts that claim to be machine washable shrink and need prior knowledge to keep them wearable.

The physical world is complex.

Interestingly most detergent works great at 30c. Hotter wash temps are for a time before biological enzymes were used as detergent additives.

[mikestew]

The detergent we buy works fine at whatever the water temperature is coming out of the cold side of the tap. I don't know that we even need to have the hot water line connected at our house as I don't recall the last time I used any temperature other than "tap cold" (I'm really curious what plain old "cold" does; is there a chiller in there I don't know about?) I mean, it's not like my chemical engineer classmates were sitting on their asses the last 30 years, modern detergent ain't the stuff your Mom used.

And lest one think I'm a dainty flower that doesn't get clothes all that dirty, just last week I was running a trail race, and as I do, caught my foot on a root and went diving downhill straight into a big pile of Pacific Northwest mud. I wasn't sure the mud was going to wash out of my skin, let alone the knee socks and running outfit. One trip through the front loader on cold, and it's like it never happened.