from GE Flight Operations Newsletter, Vol 1, Issue 1, Fall, 2006
"An additional means to save fuel during flight operations is
optimizing the use of reverse thrust when operating
conditions allow. Again, it is important to consider all FCOM,
performance, airline and safety procedures in the evaluation
of the amount of reverse thrust to use. Obviously the benefit
of reduced fuel burn and reduced FOD ingestion associated
with lower than maximum reverse thrust must be weighed
against operational requirements, the potential for increased
brake wear and the operational considerations associated
with the potential for increased brake temperatures. The
potential fuel savings, assuming idle reverse thrust is used on
all engines for 20 seconds, are shown below."
I can't get the table to copy, but it shows;
CF-34 39lbs (2 engines)
CFM-56 30lbs (2 engines)
CF-6-80 137lbs (2 engines)
CF-6-80 267lbs (4 engines)
GE-90 149lbs (2 engines)
as the average difference between idle and full reverse for 20 seconds....