Seems the alternative engine proposed for MS-21 which is Pratt & Whitney’s PW1000G geared turbofan is much more sophisticated and fuel efficient than the Aviadvigatel PD-14 twin-shaft turbofan.

Much of the claim of MS-21 fuel efficiency is based on the use of American engine.

Capability wise how well does the PD-14 engine compare to their western counterpart ? Specially the PW1000G engines ?

http://www.avid.ru/eng/advanced-developments/Regional_Jet/