Some sample numbers from the book to illustrate:
For a 390T aircraft to climb to optimum CRZ alt:
CF6-80C2B1F: 18mins & 7500kg
PW4056-3: 20mins & 8100kg
RB211-524H2: 19mins & 8100kg
Long Range Cruise at optimum alt for 390T (The PW and RR fall behind slightly further for lighter weights):
CF6-80C2B1F: 13144kg/h
PW4056-3: 13184kg/h
RB211-524H2: 13328kg/h
The GE and PW are pretty close overall in the cruise with the Rolls lagging behind by about 1.5%.
Interestingly in climb performance the CF6 really shines for some reason.
Having flown all three engine types, I have to say the CF6 is a joy to start, very quick to spool up while the PW and RR take an age to get going (God help you if its summer and you're in Nairobi or Addis).
PW very reliable though, once had an ENG OIL FILT contamination message which would have meant retarding the thrust and possible shutdown in a CF6 but PW decided having a secondary filter was worth it, no action required.
The Rolls does have one thing going for it however, it by far sounds the best of the three!
Telekon