The 5% gradient published for 757 and 767 at MLW is one size fits all. The aircraft will manage at least this figure at all temperatures with a crook donk.
Thanks for that, we operate the B777, for one particular airport with a 6% MAP gradient, we have a band of landing weights versus temperatures of over 40,000 kgs! Hence my interest in the single value for the 757/767.
Cheers.
Mutt.