A320 family, 737 Classic, 737NG & 757 maintenance cost comparison, Issue 25 Oct/Nov 2002

Maintenance costs are one factor that determine which of the Airbus and
Boeing narrowbody families are more efficient. Analysis of all airframe and
component elements reveals little difference between either family.
Despite having some disadvantages of an older generation, the 757 is
more efficient on a cost per seat basis.