i've washed my 772s many many times in hot water, plus dried on high heat. the length did not shriink at all. they do shrink in the waist a little bit, but return to normal after a few wears. i only do this to them because i lost some weight since i bought them, but have been too cheap to get another pair in a smaller size. they are a size 31x30. after washing/drying, on first wear they feel like my 30x30 zathans. after many wears, they are practically falling off. only after i purchased them did a diesel employee tell me that the 772 stretches up to a whole size.
i have never washed my 770 zathanss in hot water. i think i washed them warm on accident once, and they shrank in length by about half an inch. i always dry them on low heat for only a few minutes then i take them out and hang dry them. the 770 is a very stiff denim and does not have much give. the denim has not gotten noticeably softer since i've purchased them, but they are still pretty comfortable.. the good thing is that they do not stretch out much after repeated wears.
the 888 zathans i have washed in hot water once or twice because they felt a little big. they are a size 29x30, but felt bigger than my 30x30 zathans. they shrunk quite a bit in the waist, but not much in length. i probably will not wash them hot ever again because the denim seems to have shrunk permanently, since after repeated wears they have the same tightness. which is good though, because before they were a bit loose.
the 80y zathans i have washed hot numerous times. stretch denim is tricky. when i first purchased the pair, they felt perfect. but after repeated wears they stretched out a lot. after washing hot they are very snug, but always stretch out again. they did not lose any length. there is some permanent shrinkage with this wash because after repeated wears they never stretch out as much as they did when i first bought them.
when i went to the diesel store to try on the 82h zathans, the employeed told me to go down a size. i guess they just run big. that's unfortunate if your only option is buying them online, since there is really no way you would know that.
in my experience washing hot has not taken out any of the wash on any of the jeans i own. not to say that all diesel washes are like this. but that is just what i have experienced. i alway turn inside out,