Hi,
I noticed ATR-42 300s consume less fuel than ATR-42 500/600s. Arent the newer aircraft supposed to be more fuel efficient?
The 500/600 have a faster rate of speed, so the flights are a bit shorter and you can do more per week. Accordinging to your comparison posted the -300 is 40 flights per week, while the -500/600 have 44.
But that doesn't explain the fuel consumption ;)
The problem of the current system - we calculate the fuel consumption on the weights and sometimes this is resulting to not matching results like these posted above. We are working on a new system but until then, we have to get along with the current values.