[zipper]

Airbus had built a larger engine that was more fuel efficient

Pratt & Whitney makes the GTF-design series engines.

They are more fuel-efficient, much quieter, and have lower levels of toxic emissions than the GE engines on the Max.

https://www.pw.utc.com/products-and-services/products/commercial-engines/Pratt-and-Whitney-GTF-Engine/

[WashingtonSource]

Interesting. Thanks.