In movie 2007, the official height of Optimus is 8.5 metres. But it seems to have changed to about 10 metres in ROTF. And in ROTF, Epps said Optimus' weight was 10 ton. That means Optimus is as heavy as a male mammoth, heavier than a male African elephant, and much heavier than a male Indian elephant. But that makes me think of another question - since a Transformer could "change" his/her height/look, would he/she always keep the same weight? Or his/her weight would change according to his/her vehicle form's weight? Eg. is movie Bumblebee of his own weight? or the same weight as a camaro? Sorry for my not-good English. Hope you know what I mean.