Engines and things and Butterfly Wings
If you want a decent answer to a tech question then ask an Engineer. So here I go.
Why is the RB211 G4/H4 more efficient than earlier RB 211 especially on QANTAS aircraft. Is GE CFC 80C2 a better engine than the PW JT9 7R4 or in particular is a PW better than a GE and is the RR RB211 better on a 767 -300 series thaqn the GE series.
PS I have looked at the Rolls Royce and QANTAS web page but the info is not specific enough. Thanks for any info on the above.