I've seen the recommendation in here to change the oil when it is warm but not hot. Is this advice to save your skin or is there a mechanical/engine damaging reason?

Saving your skin is certainly an important consideration!

I personally believe that there is a large advantage to changing your oil HOT and OFTEN. When I drain my oil, I try to do it on a Friday night as soon after driving into the garage as possible. Yes it is uncomfortable, but you can always just use a wrench, let the plug fall in the pan, and then fish it out after the oil is cool.

My Friday night oil change is so that it can drain at least over night. If you drain the oil hot, more contaminants are suspended in the oil, rather than clinging to everything inside the engine. Draining it overnight allows every last bit of "gunk" to come out. The sludge and gunk come out last.

I personally believe that changing oil hot and often is even more important than the particular oil brand that you use. Most oils, unless your talking about the cheapest discount store brand you can find, have adequate lubrication properties, it's the additives that vary. Most of these additives are there to keep your engine internally clean.

Warm is better than cold, but hot is better than anything.

I drive 50k to 70k per year and although I can't prove that my frequent changes and extreme methods are extending engine life, my 240D went 516,000 miles before engine failure. I would expect that this is saying something.

Good luck and be careful with the hot oil.

Larry

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Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
Over 800,000 miles in
Mercedes automobiles