B777 fuel jettison

[applecrumble]

FCOM says for a -200 5200kg will be left in each main tank. For a -300 it says 3800kg will be left in each main tank.
Anyone know why there is the difference?

[TURIN]

Which engines do you have on the - 200? Could it be that?

[skkm]

It's a difference that was introduced in production several years ago- on our fleet newer-built aircraft are 3800kg and older ones 5200, even within the same variant.