Avianca and Volaris have both received international Aero Engines' "Pure-V" designation for their V2500 engines.
Engines in the programme are shown to have parts and repairs approved by the OEM.
Avianca has 33 Airbus A320s with the V2500, and Volaris has chosen the engine to power 14 of its A320s.
"OEM maintenance agreements help reduce fuel consumption, have fewer removals and help maintain residual value as well as engine reliability," says Volaris chief executive Enrique Beltranena.
IAE says that engines maintained to its standards have 20% longer on-wing time between maintenance visits than those that are not.