A UPS Dispatcher here. I see the fuel burn numbers everyday with Pratts and Rolls on my desk and the Rolls burn more. More than a few times I'll have a SDF-west coast flight swap from one engine type to another and occasionally I'll get a call questioning the fuel burn. CI555 to the coast on an average plan and the burn difference depending on the PH of the stratosphere (kidding!) may be as high as 4,000 pounds. Just an observation from the sidelines here, not entering a debate on which is the better engine.

Regards,

CV-880