Transatlantic London City (LCY)

wonder why BA chosse the A318 instead of the E175? is it b/c of fleet commonality? They are roughly the same size but the A318 is wider

About 1100 nautical miles.

Also, the A318 is about 35% bigger by seatcount.

Could it also be the A318 is ETOPS certified while the E175 may not be so certified?