Hi i juz wish to check can i use boeing to compare my design for 200 passenger?..i mean like i am not going to build it (duh)...but juz comparsion.
questions that had been arise so far:

1.Why issit that some aircraft is more fuel effcient than other..(wat izzit that is fitted inside) or any reasons?
2. how does the wing geometry helps in the aircraft as in the diff designs?
thanks![8D]