|Quoting RJ111 (Reply 2):|
People have already said it's lighter than the a300, so they must now how much it weighs.
ASAIK, the 787-3 will have an OEW a minimum
of 2,000 lbs heavier than the A300. It will have compromises due to the fact that the -8/9 are the primary emphasis of the 787 program and will be more optimized variants. Since OEW isn't working for the -3, Boeing will likely ride propulsion, aerodynamic, system improvements, and more revenue potential to make a case against the A300.
Here's some generalized info that might be pertitent-