Twin v Four engines
Why did Airbus build the 340 with four smaller engines, and the 330 with two larger engines? The 340 has longer range, and this obviously requires more power to lift the additional fuel off the ground, and up to cruising altitude. But could this not have been achieved with two larger engines (as per the 777)? Is there any reason why four smaller engines would cruise more economically at altitude than two large ones? The ownership costs must be higher for four engines with the additional maintenance burden etc.